I know this is an older post but I recently had this problem and just want to say that the problem was actually the Trillian IM program which I guess had assigned shift-ctrl-i to some function of it's own. If you right click on Trillian and close it (or kill it through task manager, which is a good way to find out what's assigned that hotkey but make sure you know what process you are killing first!) you'll get your hotkey back. Hope this helps someone.
I know a few people had mentioned this already but just to make things very clear I wanted to post this. Thanks. -- <http://forum.pspad.com/read.php?2,36922,42864> PSPad freeware editor http://www.pspad.com
