Yeah. When I plug in my laptop it uses 100% CPU, bringing everything to a halt. Unplug it and bam, fine. What gives?
This is also interesting because it's dual-core. That'd mean a single thread can only use 50% CPU, which I've seen many times. Wtfux?
I guess one question is, which operating system are you using?
Windows Vista.
Also, this apparently only happens while plugged in and NOT charging. :-\
It was a feature of Vista Battery Saver gone awry. I uninstalled it since it didn't do much anyhow.