Getting a weird issue with decrypting

[VaasKahnGrim]

sometimes when encrypting a string, and decrypting it later there seems to be a chance of inconsistant results. when writing the string into a file it appears that when decrypted there are null characters after the original string in the file that the dencrypted string is written to.

Is this normal and if not is there a chance of having that patched to return the original string without the null characters at the end of it?