It started happening about a year ago, I guess when the $$ from eBay poured in and Skype became a supermarket for too many features.
Meet Skype, the new CPU-hog in your computer.
Constantly with 5-10% CPU, more than 50MB of RAM and constant hard-drive access. The image below is 2 minutes after opening Skype and a single phone call.
So if you mainly initiate calls, switch to Jajah. Better phone quality (since the call is direct), same/better rates and you don’t need to donate your CPU time to anyone.
I wish Skype released mini-Skype, or better off, made available their 2.0 version.