>I understand that principle, but how does the editor know what the functionality is of a hundred lines (an arbitrary number) of code?

Some SWAGs:

- Is there any complication involved e.g. are you working in a Remote Desktop session, in a virtual machine etc.?

- Are there any add-ons in use e.g. editor enhancements for Visual FoxExpress, Visual MaxFrame Professional etc.?

- Have you installed the mouse utilities for your exact make/model of mouse, and do those utilities recognize it properly? Just making sure you're not using Microsoft utilities with Logitech mice etc.

- Are you using any sort of advanced nVidia or AMD desktop management utility with non-default settings?

- Do you use "large fonts" in Windows i.e. anything more than the default 96dpi?

I was also going to suggest temporarily renaming your FOXUSER.* resource files but you say you have the same problems with VFP7, which is probably using different resource files, so that's probably not it. If you still want to try it you can find your current resource file with ?SET("resource", 1) .