I was finally able to decode it but you're doing it wrong. You encrypted the message then you signed the encrypted message and then you re-encrypted it plus some plain text. You should encrypt it and signed it in a single step so it can be decoded at once. What client are you using? For example on Cryptophane you can do it in a single step:
I am using gpg4usb. I am actually doing it this way -
1. Sign the messages [ Recipient sure that i wrote it]
2. Encrypt it [ Obfuscation ]
3. Sign again [ Recipient sure that i encrypted it also ]
4. Encrypt again [ Not necessary well]
Now if i encrypted the message and signed it, the recipient is sure that the sender encrypted it but how to confirm the original message is written by the sender. Did anyone else write it and it was encrypted by someone else somehow
I have read this paper discussing weaknesses of either approach -
http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html