It may be conflicting with another program that's running.

It seems that we can establish that it is not "vanilla" XP-SP1 or WhatPulse that is generating the issue.

From previous posts, it appears that Lisa has re-downloaded and re-installed TKC with the same result.

It works for me on a variety of systems too, in tandem with WhatPulse.

Without being able to bench test your system, running it with and without other apps and services, I can't offer any further constructive advice.

On the upside, Lisa, you can consider yourself a 1-in-a-million chance winner. :D