>>Nadya,
>>
>>You seem to be answering your own questions today...
>>
>>Now for the 2nd part of the quetion (before you answer it)
>>
>>vfp gets kind of confused if you use a class. Things are cached in memory.
>>Write yourself a little prg (eg env) that does those kind of things like clear all, ....
>>
>>make a habit of following sequence
>>- modify a class/prg/form
>>- test it
>>- do env
>>- back to top
>>
>My question is: is it avoidable at the programming level?

Yes, method described above

I am doing this sequence for years now and have never had any problems since.
ie, before editing you have to release all instances of a class + clear any cache, reset lib, classlib, procedure, ... This is the only way I know to force vfp to discard it's internal cache and read all of it back from disc

>
>>If you don't, the sources of the classes/forms may sometimes disappear for a while
>
>Got it once :(