>Hi,
>
>I'm using VFP 5.0a. I have a form with a page frame containing 8 pages, 7
>of them with a grid. When I switch between the pages, eventually I get an
>Illegal Operation error. The problem is that there is nothing consistent
>about the pages which result in the error. IOW, it doesn't always happen on
>the same page. Sometimes the page will display fine, other times it gives
>me an error. Sometimes it happens on a page that I've selected before in
>the session, sometimes it happens the first time I try a particular page.
>It doesn't make any difference which order I select the pages in. I thought
>it might be that I was switching pages too quickly but slowing down doesn't
>help. Other times I can switch as fast as I can move the mouse and nothing
>happens.
>
>Based on all this, I doubt it's my code. Otherwise I would get the error
>the first time I hit the page. I thought that maybe the form was too large
>for a PC with only 16MB or RAM but, if that were the case, wouldn't it
>always blow up after the same number of pages?
>
>I know there's not going to be any quick answers on fixing this but if you
>have any advice on where to start looking, that would be very helpful.
>
>
>Gary J. Sibio

There are about 10 KB articles @ Microsoft about Illegal Operations & Page Faults. Some have work arounds

HTH