diff --git a/lib/msf/core/encoded_payload.rb b/lib/msf/core/encoded_payload.rb
index ee46f41405..4b0b43f535 100644
--- a/lib/msf/core/encoded_payload.rb
+++ b/lib/msf/core/encoded_payload.rb
@@ -97,6 +97,10 @@ class EncodedPayload
 				# Try encoding with the current encoder
 				begin
 					self.encoded = self.encoder.encode(self.raw, reqs['BadChars'])
+				rescue SyntaxError, ArgumentError
+					wlog("#{pinst.refname}: Failed to encode payload with encoder #{encoder.refname}: #{$!}\n#{$@.join("\n")}",
+						'core', LEV_2)
+					next
 				rescue
 					wlog("#{pinst.refname}: Failed to encode payload with encoder #{encoder.refname}: #{$!}",
 						'core', LEV_2)
diff --git a/lib/rex/arch/x86.rb b/lib/rex/arch/x86.rb
index 8d29485f31..401cae04de 100644
--- a/lib/rex/arch/x86.rb
+++ b/lib/rex/arch/x86.rb
@@ -111,19 +111,19 @@ module X86
 		# try push BYTE val; pop dst
 		begin
 			return _check_badchars(push_byte(val) + pop_dword(dst), badchars)
-		rescue RuntimeError, RangeError
+		rescue ::ArgumentError, RuntimeError, RangeError
 		end
 
 		# try clear dst, mov BYTE dst
 		begin
 			return _check_badchars(clear(dst, badchars) + mov_byte(dst, val), badchars)
-		rescue RuntimeError, RangeError
+		rescue ::ArgumentError, RuntimeError, RangeError
 		end
 
 		# try clear dst, mov WORD dst
 		begin
 			return _check_badchars(clear(dst, badchars) + mov_word(dst, val), badchars)
-		rescue RuntimeError, RangeError
+		rescue ::ArgumentError, RuntimeError, RangeError
 		end
 
 		raise RuntimeError, "No valid set instruction could be created!", caller()
diff --git a/modules/encoders/generic/none.rb.ut.rb b/modules/encoders/generic/none.rb.ut.rb
index fde902fa56..fdf5f24de3 100644
--- a/modules/encoders/generic/none.rb.ut.rb
+++ b/modules/encoders/generic/none.rb.ut.rb
@@ -1,6 +1,7 @@
 #!/usr/bin/ruby
 
 $:.unshift(File.join(File.dirname(__FILE__), '..', '..', '..', 'lib'))
+$:.unshift(File.dirname(__FILE__))
 
 require 'test/unit'
 require 'rex/ui'
diff --git a/modules/encoders/x86/call4_dword_xor.rb.ut.rb b/modules/encoders/x86/call4_dword_xor.rb.ut.rb
index e03dca2e1e..c126f0cb9f 100644
--- a/modules/encoders/x86/call4_dword_xor.rb.ut.rb
+++ b/modules/encoders/x86/call4_dword_xor.rb.ut.rb
@@ -1,6 +1,7 @@
 #!/usr/bin/ruby
 
 $:.unshift(File.join(File.dirname(__FILE__), '..', '..', '..', 'lib'))
+$:.unshift(File.dirname(__FILE__))
 
 require 'test/unit'
 require 'rex/ui'
diff --git a/modules/encoders/x86/countdown.rb b/modules/encoders/x86/countdown.rb
index 62273af79d..c8f663b02e 100644
--- a/modules/encoders/x86/countdown.rb
+++ b/modules/encoders/x86/countdown.rb
@@ -28,8 +28,9 @@ class Countdown < Msf::Encoder::Xor
 	#
 	def decoder_stub(state)
 		decoder = 
-			Rex::Arch::X86.set(state.buf.length - 1,
+			Rex::Arch::X86.set(
 				Rex::Arch::X86::ECX,
+				state.buf.length - 1,
 				state.badchars) +
 			"\xe8\xff\xff\xff" +
 			"\xff\xc1" +
diff --git a/modules/encoders/x86/countdown.rb.ut.rb b/modules/encoders/x86/countdown.rb.ut.rb
new file mode 100644
index 0000000000..d78159bfd0
--- /dev/null
+++ b/modules/encoders/x86/countdown.rb.ut.rb
@@ -0,0 +1,43 @@
+#!/usr/bin/ruby
+
+$:.unshift(File.join(File.dirname(__FILE__), '..', '..', '..', 'lib'))
+$:.unshift(File.dirname(__FILE__))
+
+require 'test/unit'
+require 'rex/ui'
+require 'msf/core'
+require 'countdown'
+
+class Msf::Encoders::X86::Countdown::UnitTest < Test::Unit::TestCase
+
+	Klass = Msf::Encoders::X86::Countdown
+
+	def test_encoder
+
+		k = Klass.new
+
+		{
+			"\xcc\xcc\xcc\xcc" => 
+				[
+					"\x6a\x03\x59\xe8\xff\xff\xff\xff\xc1\x5e\x30\x4c\x0e\x07" +
+					"\xe2\xfa\xcd\xce\xcf\xc8",
+					4
+				],
+			"ABCDEFGHIJKLMNOPQRSTUVWXYZ" =>
+				[
+					"\x6a\x19\x59\xe8\xff\xff\xff\xff\xc1\x5e\x30\x4c\x0e\x07" +
+					"\xe2\xfa\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40" +
+					"\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40",
+					4
+				]
+		}.each_pair { |raw, real|
+			offset = real[1] || 0
+
+			encoded = k.encode(raw, '')
+
+			assert_equal(real[0][offset, -1], encoded[offset, -1])
+		}
+		
+	end
+
+end
diff --git a/modules/encoders/x86/fnstenv_mov.rb b/modules/encoders/x86/fnstenv_mov.rb
index 8f52427b75..81e1a03cd8 100644
--- a/modules/encoders/x86/fnstenv_mov.rb
+++ b/modules/encoders/x86/fnstenv_mov.rb
@@ -29,8 +29,9 @@ class FnstenvMov < Msf::Encoder::Xor
 	#
 	def decoder_stub(state)
 		decoder = 
-			Rex::Arch::X86.set((((state.buf.length - 1) / 4) + 1), 
+			Rex::Arch::X86.set(
 				Rex::Arch::X86::ECX,
+				(((state.buf.length - 1) / 4) + 1), 
 				state.badchars) +
 			"\xd9\xee" +              # fldz
 			"\xd9\x74\x24\xf4" +      # fnstenv [esp - 12]
diff --git a/modules/encoders/x86/fnstenv_mov.rb.ut.rb b/modules/encoders/x86/fnstenv_mov.rb.ut.rb
new file mode 100644
index 0000000000..e75a317879
--- /dev/null
+++ b/modules/encoders/x86/fnstenv_mov.rb.ut.rb
@@ -0,0 +1,44 @@
+#!/usr/bin/ruby
+
+$:.unshift(File.join(File.dirname(__FILE__), '..', '..', '..', 'lib'))
+$:.unshift(File.dirname(__FILE__))
+
+require 'test/unit'
+require 'rex/ui'
+require 'msf/core'
+require 'fnstenv_mov'
+
+class Msf::Encoders::X86::FnstenvMov::UnitTest < Test::Unit::TestCase
+
+	Klass = Msf::Encoders::X86::FnstenvMov
+
+	def test_encoder
+
+		k = Klass.new
+
+		{
+			"\xcc\xcc\xcc\xcc" => 
+				[
+					"\x6a\x01\x59\xd9\xee\xd9\x74\x24\xf4\x5b\x81\x73\x13\x3e" +
+					"\x33\x75\x05\x83\xeb\xfc\xe2\xf4\xf2\xff\xb9\xc9",
+					4
+				],
+			"ABCDEFGHIJKLMNOPQRSTUVWXYZ" =>
+				[
+					"\x6a\x07\x59\xd9\xee\xd9\x74\x24\xf4\x5b\x81\x73\x13\x39" +
+					"\xaf\x73\x32\x83\xeb\xfc\xe2\xf4\x78\xed\x30\x76\x7c\xe9" +
+					"\x34\x7a\x70\xe5\x38\x7e\x74\xe1\x3c\x62\x68\xfd\x20\x66" +
+					"\x6c\xf9\x24\x6a\x60\xf5\x73\x32",
+					4
+				]
+		}.each_pair { |raw, real|
+			offset = real[1] || 0
+
+			encoded = k.encode(raw, '')
+
+			assert_equal(real[0][offset, -1], encoded[offset, -1])
+		}
+		
+	end
+
+end
diff --git a/modules/encoders/x86/jmp_call_additive.rb.ut.rb b/modules/encoders/x86/jmp_call_additive.rb.ut.rb
index eaf4b5db4c..38d4ab3aa7 100644
--- a/modules/encoders/x86/jmp_call_additive.rb.ut.rb
+++ b/modules/encoders/x86/jmp_call_additive.rb.ut.rb
@@ -1,6 +1,7 @@
 #!/usr/bin/ruby
 
 $:.unshift(File.join(File.dirname(__FILE__), '..', '..', '..', 'lib'))
+$:.unshift(File.dirname(__FILE__))
 
 require 'test/unit'
 require 'rex/ui'
diff --git a/modules/modules.rb.ts.rb b/modules/modules.rb.ts.rb
new file mode 100644
index 0000000000..a4b9eaf7a1
--- /dev/null
+++ b/modules/modules.rb.ts.rb
@@ -0,0 +1,26 @@
+#!/usr/bin/ruby -I../lib
+
+$:.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
+
+require 'test/unit'
+
+require 'encoders/generic/none.rb.ut'
+require 'encoders/x86/call4_dword_xor.rb.ut'
+require 'encoders/x86/countdown.rb.ut'
+require 'encoders/x86/fnstenv_mov.rb.ut'
+require 'encoders/x86/jmp_call_additive.rb.ut'
+
+class Rex::TestSuite
+	def self.suite
+		suite = Test::Unit::TestSuite.new("Rex")
+
+		# General
+		suite << Msf::Encoders::Generic::None::UnitTest.suite
+		suite << Msf::Encoders::X86::Call4Dword::UnitTest.suite
+		suite << Msf::Encoders::X86::Countdown::UnitTest.suite
+		suite << Msf::Encoders::X86::FnstenvMov::UnitTest.suite
+		suite << Msf::Encoders::X86::JmpCallAdditive::UnitTest.suite
+
+		return suite;
+	end
+end