Hi Victor,
You are not alone...
I asked these in the past - why CLEAR CLASSLIB does not work, and why cannot you check what classes are in memory, or why are they left in memory after an exe exits. It may not be related (but I feel it is), from time to time our users get forms (.scx/.sct) in use when running .EXE files with the forms included. We are still looking for answers...
We have this code in a .prg to clear classes from memory, in development:

dimension laClasses[1]
store '' to laClasses
avcxclasses(laClasses,'theClassLib')
lnAlen = alen(laClasses)
for lnCount = 1 to lnAlen step 11
    clear class (laClasses[lnCount])
endfor