Sergio,
I would not try to use the same classlib between two different versions of VFP. You should have a VFP6 and a VFP7 version of your library.
Make a backup first and try to issue a COMPILE CLASSLIB xyz in VFP6 to see if that will make the classlib useable in there once again.
>I'm having a problem openining forms up in 6.0, that were created in 6.0, after having opened them in 7.0. The code in the object events is all offset and scrambled. If I open the form with "modify form ?" its okay. I think it has to do with the codepage, but I'm not sure. Any ideas?