Doug Stewart has posted an extensive list of CRL 2.0 bug (hot)fixes. Its worth a look if your Dot Net 2.0 app is having issues. Thanks for putting together such a comprehensive list Doug.
I have seen this issue on a QA server The managed heap becomes corrupted when you run a program that is built by using the Microsoft .NET Framework 2.0 good to see its not my code and that there is a fix for it.
Some of the Hot fix support articles do leave a little something to be desired though I would like to see Microsoft spend the time to detail the cause for each issue so I can better evaluate my need for a given fix.