CPU gone wild!

Last night i had a DJ friend of mine on visit at my studio.
We discussed FS2 and all the advantages and it all led up to a test drive. At this moment i had the LapTop that im using for FS connected to the mothership for some new MP3s. I disconnected the FW and change the location of the laptop closer to my DJ set up.
Connected the SA and restarted the LT.
Everything was loading just fine and we started to mix.
I like to show off so i played the 45 rpm vinyls and hit the keylock for some 33 rpm action. Played some house tunes at 127 bpm turned off the power and restarted at 33 rpm did the mix "low beat style" and increased the speed by hand up to 45 rpm again. at this point the sound got really crazy with distortion. i turned of the key lock and we were back to normal. BUT at this point i did a CPU check and the CPU was running wild. readings round 75-100%
What the ****. restarted, changed the FW cable, nothing.
OK stop and think. have i changed anything since last time?
Yes i had, the laptop was connected to another powerplug than the rest of my setup. I replugged with the DJ set up, restarted and it was all back to normal again. Can anyone explain this?
Sorry if this message was "long"

 

One word.. GROUNDLOOP.

 

But how could this effect the CPU?
My lap top is not grounded at all since it is equipped with a flat powerplug.
In my world this seems very strange but on the other hand im totally lost if we go deeper into electronics.

 

The reason why a ground loop would affect this, is because a ground loop is audible, and would cause additional sounds to be introduced into signal chain, causing FS not to get a clean signal from the timecode, thus causing the key correction to work overtime.

Hobbes

 

Thats right, first i checked the needles cos i felt it would be a time code problem. Now i see why it was like that. Thanx