>Check http://blogs.msdn.com/calvin_hsia/archive/2006/03/28/563138.aspx
>
>Unfortunately, I was unable to find more info on Foxuser internals.

Thank you for this tip, Naomi. I learned a little bit more about foxuser, though presently I do not see any possibility to appy this knowledge to this funny problem. But who knows...

I think, the cause of the "disappearing column" behaviour is outside of the foxuser.dbf, which only preserves some settings, which then will cause this. Therefore I will do as announced: Make a new foxuser.dbf and watch out for the next time this is going to happen.

Again many thanks!