[LUAU] Fedora & mythtv cpu load

[Whoever Whatever]

Hi,
   I was running Mandrake 9.2 for mythtv up to .18.1 on a shuttle
sk41g using PVR350 for about 2 years, nvidia tv-out, no problem
watching live tv or recording while compiling.  So, I decided to
switch to Fedora core 3 few weeks ago, aptrpm get the mythtv-suite, it
stutter a little when starting live tv, the frontend using about
25-32% of the cpu load, video/audio hicup when I did apt-get update,
then I decided to re-compile some plugins today, live tv or playback
un-watchable, it pause and/or stutter while compiling. Does anyone
know have experience why fedora so much slower on the same hardware? I
was hunting for the cause for a while, but not able to trace it down. 
 HD is enabled with DMA,  using KDE as WM, the only difference would
be xorg server on fedora, xwindow on Mandrake.  Thanks for the help.

SK41G, VIA chipset, AMD 2400+ xp, 512mb DDR266, WD 160Gb hard driver,
onboard VIA sound, nvidia AGP MX420 with tv-out, PVR350.

Thanks