Cannot create snapshots - Bug? Unsopported?

Hi all,

as the subject says, i am unable to take snapshots of the current program.
Neither kdetv 0.8.3 nor the current cvs work.
I only get a not much telling message 
"Error grabbing image. Snapshots may not be supported with this plugin." 
also on console no more information. Console just says 
"Kdetv: Creating snapshot of size 768x576" nothing more.

So: which plugin does not support snapshots? v4l or XVideo? Or the driver of 
X11? I don't trust that driver (3dfx/tdfx) very much, but kwintv 0.8.12 
works! (well, at least the snapshots)

I also have to use the XVideo driver, if i disable it in kdetv and only use 
v4l i run into that empty-configuration-dialog. :(

So any hints?

System:
SuSE 9.0
kernel 2.4.27 built by myself
X11 4.3.0.1
kdetv from cvs, checked out today

regards,
Tim