Now you say timer.
I have the same error occuring over and over.
But I use a timer to check if some of my forms are still in edit mode (its some trickery with VSS automation, cause VFP under VSS-control is soo slooow).
Once the files are to be checked out, one out of three times I have that error.
Then I see that the file was correctly checked out, so everything OK up to there.
Meanwhile lots of object references are passed between the 3 objects I use, this to be able to communicate between the three of them.
So I think it definitely has also somlething to do with the object references badly cleared out and the timerinterval.

I will keep on investigating this one.
Keep you all informed.