Massive Compression Times

[blobb57]

I am starting to get massive compression times, like 6 hours or more if i choose DVD -> Mobile, after having copied to hard disk (as per good practice guide). Irrespective of whether I choose Xbox (WMA) which would be my preferred choice, as these files obviously maintain their audio qualities, but also stream beautifully via TVersity to my PS3, or even if I try AVI, with XVID audio...it's really frustrating.
Does anyone have any idea's?? I have a HDD full of WMA's that play perfectly, video quality is fantastic too - and I would love to continue expanding my collection!!

Thanks

[Complication]

Some PC's will step down the processor speed when there is heat buildup (especially laptops). You might check to make sure your fans and vents are clear of dirt and working.