David,

>All of a sudden, all the methods to a class in one of my class libraries disappeared. I USED the vcx, and interestingly, I couldn't get exclusive access (even after restarting my machine).

This happened to me the a couple of weeks ago. Restart VFP, do no try to MODI CLASS, because what's happening is you have a property or method that VFP can not compile, and it puts VFP in a state where it can't release that row of the classlib.

If you just USE the classlib and go to the trouble causing class. Examine the Properties memo first and then the Methods memo. Look for things like character strings that are improperly quoted or not quoted at all.