>>>Weird, and sounds like a real bug. Couple of things I'd check - see if file("myheaderclass.prg") returns .t. from within the grid setup code, and what is the set("procedure") returning at that point. Somehow this seems that the grid setup is firing far earlier than we may think.
>>
>>While I have no idea why this was a problem, the problem was that I couldn't pass more than 4 parameters to the form. It had nothing to do with the headers. So I collected the parameters into an object and passed the object and now all is well. This has to be the craziest bug I've encountered. Thanks to all who tried to help!
>
>Goes directly to Weird Bugs Hall of Fame. We don't have one? We could start a document on that...

There is the emtire chapter at the Russian VFP Club site for VFP bugs ;)
BTW, in VFP5 there were some problems with passing parameters to forms too, as far as I remember...