ToBase64String And FromBase64String?

I have a crypto class where strings like a passwod or email address are encoded and decoded.

I'm having problems with the ToBase64String and FromBase64String methods.

In the crypto class, the string is encoded first and then converted to a base64 string.

When decoding it, it's first converted from base64string to an byte array which is then decoded.

If I encode a certain email address it and then later I want to decode it again, I get an error.

The error is: "Invalid length for a Base-64 char array."

I tried it first with coding with DES and also tried it with tripleDes, but the result is the same.

This is causing a lot of problems. How can I solve this?

Here is some code:

[Code]...