Typing issues

This has been happening since I bought the system. I am running Vista SP1. When I am typing in a field it will suddenly stop typing and I have to click somewhere else on the page and then back in the typing field in order for it to allow me to continue typing. I am thinking that this is a FF3 issue since I had no troubles with it using Opera but unfortunately Opera does not work on a lot of the sites I visit so I am stuck with FF3. Has anyone experienced this and is there a fix within Windows or FF that can correct the problem? Thanks for any and all help.

 

Bumpity bump bump