xawtv hard freeze in overlay mode on P4S8X with GeForce4 MX440

[Christian Buchta <christian.buchta@xxxxxxxxxxxxx>]

I recently bought a P4S8X mobo with an Intel P4 2.66 and 1G RAM, 
IDE/ATAPI disk and dvd writer, installed my Pinnacle PCTV Pro card and 
DEBIAN testing with kernel 2.4.20 (686) and KDE (2.2.25). Initially I 
used my old Trio64V2/DX based gaphics card on XFree 3.3.6. There were no 
problems with xawtv (3.72) in overlay mode. Then I replaced the graphics 
card with a Geforce4 MX440 (CREATIVE) and installed XFree 4.2.1-3. Under 
both drivers, XFree's nv and Nvidia's (from the latest release), the 
system freezes immediately if xawtv runs in overlay mode and I move some 
window, say xawtv or the konsole. In grabdisplay mode no problems occur. 
On Nvidia's Linux forum I found similar reports but no real good hint 
where to start fixing the problem.

Yesterday I played around a bit with the latest KNOPPIX release (3.1), 
and to my surprise no freeze occured. KNOPPIX is quite similar to my 
harddisk installation, but runs entirely from CD: they are both DEBIAN 
systems, the versions of xawtv and the kernel are the same, but XFree is 
a bit newer 4.2.1-5pre, as well as KDE. Nevertheless by the dmesg and 
XFree logs I can't  tell a difference in system or xserver setup.  

Please, give me a hint how to track the problem down. Is this more 
likely to be a hardware or a software problem? I don't feel it's a bttv 
or xawtv problem.
  
THX