Ok, I'm stumped. I'm working on a problem which only occurs on some machines (can't find anything common between these machines), and is going to drive me nuts.

What happens is, if a certain form is maximized (or sized over a certain amount), and you pull up another certain form (which is a search screen), CPU usage jumps to 100%, and the mouse acts like there's a 1-15 second delay between input and action (depending on the computer, and how large the first form is sized).

BUT, if you give the focus to another windows application, wait a second, and go back, everything's normal (back to 0% CPU). Now, the 100% CPU usage actually occurs on every machine, but the mouse remains responsive. There's no VFP code running (I've checked with SET COVERAGE and SET STEP ON).

The search form is model, the calling form is not. There are several layers of code between the code to respond to the click, and (calls a method which calls a method which calls a method which calls a method, etc). I *really* do not want to try and piece together the different methods into the same piece of code (there's a lot of it), but that's what I was going to try next. (smaller call stack?)

Also, if you pull this form up from another form, even with the first one open, no problem. I'm thinking of using a Timer as a workaround, but I don't really want to.

Any suggestions? Anyone seen this before?