>I have been experiencing several very hard to explain discrepancies between the vfp6 dev env. and the runtime exe.
>I am working on a compaq deskpro pentium 3-450 with 64meg.
>But, I have gotten similar results from other machines at a client site.
>Has anyone experienced similar problems of instability / unreliability with vfp6sp3 runtime? It has cost a great deal of time and frustration to work around these problems, and in the end, the client will run the exe from vfp6.

Your best bet would be to try to get the error down to a few lines of code and then repeat the behaviour regularly.

I have seen sporadic results like this on machines that don't have enough memory or on machines with funky video drivers. Try to set the problematic machines to a plain vanilla video driver and see what happens.