I've also experienced several crashes with 7.02, 7.03, and 7.04. I have MMYSQL loaded as well as FiSH 10 and quite a few scripts that did not cause any issues at all on 6.35. I'm not sure how much has changed in the back end as far as scripts are concerned, but if a more in depth reply is necessary I can go through them and get back to you on here.
I have yet to try the beta without mmysql loaded but to be fair, the script using it doesn't have access to the sql database so I don't think it would cause the crashes.
These crashes lock up the application on Windows 7 32-bit Enterprise, and cause the Windows Crash Recovery program (I think that's the name of it) to search the net for a solution. Sometimes they would happen seemingly random after being connected for several days. Other times it was during my connect sequence (a decent amount of znc connections).
If there is anything else I can do to help, I will try to keep monitoring this thread and I'm also on efnet as exoa or ex0a (I know you usually are as well argv).