Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.
I think that might be one of those tips that will work for some, but not everyone. Hopefully that fixes his issue. I rarely run in foll-screen anymore, and the main reason is that I used to fly Multiplayer every day and with FSHost Client and FSX you can no longer fly in full screen like you could in FS9 with FSHost. I just got out of the habit of flying in full screen along the way.Tooltips are at times a bit laggy in fullscreen mode and don't work at all in DX10 preview and fullscreen.
Either Alt+Tab to windowed mode or run in DX9 to come around the issue.