You can do two things.
a) mock about with the source and compile your own revision.
b) Implement an alternative solution. in application or browser mode.
Applications with built in supporting functions exist. See C# , C++ and VB in .NET versions.
I prefer not to use .NET but thats another story.
Browser wise you can implement it using mcrypt in PHP.
There are good enough JavaScript versions if you want to make sure things are encrypted befoe it leaves the users computer and goes online.
See:
AES Rijndael enc/dec routines for javaScript
developed and tested by Herbert Hanewinkel,
http://www.hanewin.net/encrypt/aes/aes.htm
You also need to make sure your random number generator is enough if you want to get really paranoid.
I posted an idea on this in PHP's forum recently too as there are no good, freely available PRNG's floating about unless you work in C/C++ directly.
(If so, see Yarrow and it's follow-up FORTUNA)
For my idea, see PHP forums for the function mt_srand user contributed notes.