No 3D support after custom kernel compilation

[Marino Fernandez <mjferna@yahoo.com>]

I have debian testing/unstable, gcc 3.2, kernel 2.4.20-xfs from knoppix. 3D 
support works fine (Intel830M).

I compiled a 2.4.21 kernel and noticed no 3D suport; then I compiled a 2.4.20 
(no xfs patch) and the same problem.. I used exactly the same .config file 
used for the first kernel in both cases. 

I then downloaded a tarball from DRI with the src for dri/drm support for 
I830M... ./configure && make && make install... still no 3D support.

lsmod in 2.4.20-xfs (the one with 3D support) shows i830 used 14 times and 
agpgart used 13 times. lsmod with 2.4.21 and 2.4.20 show i830 used 0 times 
and agpgart 7 times. Otherwise the rest of the modules are the same.

The files modules.dep are the same in both cases (with and without 3D 
support).

Any ideas. Thank you.