Just a couple of things, which might not help.
I see you are running xine from Slack-current, not Slack-10.2.
Have it here also with:
GL_RENDERER = GeForce FX 5200/AGP/SSE2/3DNOW!
GL_VERSION = 2.0.1 NVIDIA 81.78
but don't know if that matters.
Are you starting xine from a menu, or from command line?
Issuing "xine -help" for video drivers I get:
-V, --video-driver <drv> Select video driver by id. Available drivers:
dxr3 aadxr3 xv opengl xshm caca aa xxmc none sdl vidix vidixfb fb xvmc
and xine works fine launched from cli or Fluxbox menu.
Reading "man xine" I see this:
Enable bug report mode. It turn verbosity on, gather all output messages
and write them to a file names BUG-REPORT.TXT. If <mrl> is given, xine
will play that mrl then quit (like -pq does).
If you don't specify any MRL, you'll have to select a file by drag'n-drop.
Dragging files from the GNOME Midnight Commander (gmc), Nautilus or Konqueror is
known to work.
so you could start xine from a terminal by issuing "xine --bug-report" and see if anything useful is output.