Here is my situation:
I'm working in a Flash-based courseware environment.
Basically, has anyone encounted a situation where the down arrow key (or any key for that matter) will work on someones computer, and not work on someone elses computer? We use various methods to navigate through our courseware, most of which are clicks, but the down arrow key is used fairly often. But unfortunately, despite our best efforts, this key often does not work on clients computers. We've tried swapping out different keyboards, no luck.
We do not have the source files for the Flash, it is auto-generated by the tool we are using (which is similar to captivate, camtasia, etc).
Are you using the same browser consistently throughout testing? Sometimes browsers are the issue for such problems and not the hardware itself