Why is Skype using 100% of my CPU or more and how can I fix it?

Today I used the Mac version of Skype for the first time on my new MacBook Air 11" running Lion - v10.7.2.

To my surprise, the process was using more than 100% CPU, the CPU temperature went high, as expected, and the fan went wild! Even more, the battery went from full to critical after just one hour of the video call.

Just now, I opened Skype to get the version number - v5.3.60.1093 - with no active chats nor calls, the CPU usage went to 135.9% in the blink of an eye!

This issue seems to be all over the Skype forums, but I can't seem to find a solution.

If anybody can lead me towards a viable fix, I'd be grateful!

I found this fix on a Skype community thread:

Quit Skype, then in your home directory, look for a folder called Library/Caches/com.skype.skype and delete or rename that folder then start Skype... cpu usage should be back to normal.

If you can't find that folder, open your Terminal and simply type:

$ open ~/Library/Caches/com.skype.skype

The issue exists with all 5.x and 6.x versions. However if you downgrade to version 2.8, CPU usage will be normal (3.5% with 2.8 version vs 149% with 6.x versions). The only problem is that video chats will not work any more. But if you do not use those, it is not a problem.

I keep 6.x version for video chats and 2.8 for all-day running. So if somebody asks me for a video call, I just ask them to wait until I restart skype.