Problem with new xps m1530?

Hi guys, i recently bought an xps m1530 and there seems to be a problem with the CPU (2.4GHZ T8300), when the laptop is plugged in the CPU seems to 'stick' on one multiplier (x8) meaning that its constantly running at around 1.6GHZ and doesnt change, even under full load (i used CPU-Z and rmclock to check the speed, and orthos to stress the cpu). The odd thing is that this only happens when the laptop is connected to the mains, when its running on battery everything works as its supposed to. I have updated all drivers, looked in power options and in the system BIOS and there wasn't anything noticable wrong. Im really out of ideas of what may be wrong so any ideas would be greatly appreciated.

Thanks in advance

 

Strange... are you applying Undervolting by any chance ??

 

No im not, i was originally planning to but ended up leaving it for fear of messing something up lol, i havent overclocked or undervolted anything so far.

 

Hmm.. but did you actually install any software for it. Try remembering. Also, post a screenshot of your desktop running orthos and your full taskbar showing along with another one with your system page showing the CPU info.

 

The only software i have installed for undervolting was rmclock however i didnt alter anything at all when using it. I have uninstalled rmclock now as well because i thought it may be causing the probelm but it is still not working correctly. It may be worth mentioning that i have re-installed vista to try and sort this and that didnt help either.
Here is the image of the stress test running:


That remained pretty much the same for the whole time the test was running, the multiplier never shifted from x8

And here is one of the system info:


EDIT: ok, after a very long time talking to dell tech support it turned out to have been a faulty power adaptor