<snip>

>Thanks Roger.
>
>After the SET STEP ON executes the debugger comes up, but behind the debugger my application (the form that called the trace window) scrolls wildly.
>
>Why? - I don't know.
>
>Thanks again.

OK probably not the mouse wheel then. Is this VFP6 or VFP7 ? Is the debugger running in its own frame or in the VFP frame? Does the entire form scrolls or does a control on the form (like a grid or a listbox) scroll? Any timers on the form?

Roger