[mythtv-users] via epia m10k mythfrontend > 90% cpu load

[maestro]

hi once again,

im in the process of getting my mythbox up and running. 
its based on a via epia m10k (1ghz nehemiah core) with 256mb ram and a
120gb hdd, hauppauge wintv pvr 250.
but one thing that renders the whole thing rather useless is that
mythbackend is using about 10% cpu power (nothing wrong with that) but
the rest to the 100% is used by mythfrontend when watching live tv.
(havent tried recording yet since i want live-tv to work first)
resulting in "frame-drops" and audio - errors (repeating words and the
like, is jitter the correct expression here?)
has anyone set up a mythbox on an epia m10k before and can tall me what
i'm missing?
i use the stock 2.4.25 kernel with the epia1 patch and compiled XFree86
myself like stated on http://www.shipmail.org/~thomas/via/
the benchmarks are done at X -startup and the figure is 316 MiB/s for
SSE YUV420 copy... 
thats not that bad. 

lsmod gives:
Module                  Size  Used by    Not tainted
serial                 48452   0  (autoclean)
ivtv                   79300   0 
msp3400                16448   1 
tuner                  10920   1 
videodev                6560   3  [ivtv]
saa7115                 5888   0  (unused)
lirc_serial             7904   1 

by the way i live in pal country (austria) and have set the resolution
to 720x576 at 16bit with Option "TVVScan" "over" in XFConfig-4

so long and thanks for your help
maestro