Make problem w/ modules_install

Hi all,
I can compile 2.4.20 w/ modules just fine. When I try 2.5.67 it
compiles fine, but when I do a 'make modules_install' I get this.

<snip>
depmod: *** Unresolved symbols in /lib/modules/2.5.67/kernel/drivers/net/ppp_generic.ko
depmod: slhc_init
depmod: slhc_free
depmod: slhc_uncompress
depmod: slhc_toss
depmod: slhc_remember
depmod: slhc_compress
depmod: *** Unresolved symbols in /lib/modules/2.5.67/kernel/drivers/video/sstfb.ko
depmod: cfb_copyarea
depmod: cfb_imageblit
depmod: cfb_fillrect
depmod: *** Unresolved symbols in /lib/modules/2.5.67/kernel/drivers/video/tdfxfb.ko
depmod: cfb_imageblit
make: *** [_modinst_post] Error 1
</snip>

The kernel compiles w/o errors, same with modules, it's the modules_install that shows this problem. It seems to be rooted in the slip code or maybe the 3c59x drivers, maybe the ppp, but I'm not sure. I'll try to go through the code and see where it's coming from. Running on a P4-2.4 w/1G ram and a large harddisk. The ethernet card is a 3C905B (10/100) board.

More later, although suggestions would be appreciated.

Cheers - Andrew