Only part of the string is getting decrypted, i think it has to do with my encoding.
Here is what happens:
string s = \"The brown fox jumped
Not sure about your specific code chunk, but Jeff Atwood did a nice little library that I've used before:
http://www.codeproject.com/KB/security/SimpleEncryption.aspx
It's worth a look as it simplifies the process of encrypting things a lot, I actually had to port to C# as there wasn't a port available when I saw it. However there is now a C# port (in the comments section).