I  am experiencing the infamous sliver problem in tksurfer over VNC. I tried solving it by installing VirtualGL, but it doesn't work, I get the following error message: 

[VGL] WARNING: VirtualGL attempted and failed to obtain a Pbuffer-enabled

[VGL]    24-bit visual on the 3D X server :0.  If the application

[VGL]    subsequently fails, then make sure that the 3D X server is configured

[VGL]    for 24-bit color and has accelerated 3D drivers installed.

Window type not found!

My xorg.conf shows 24 bit color depth. I am running Scientific Linux 5.4 on a Dell PE R905 with embedded ATI ES1000 video controller. 

It might be that the ATI ES1000 doesn't support hardware acceleration, it is a rack server. Does anybody have experience with this issue? Pointers?

Cheers,

Diederick