problem compiling kernels

[Philipp Bliedung <philipp.bliedung@bliedung.de>]

Hi,

I'm new to Debian and fairly new to Linux.
I compiled some kernels (I'm using kernel 2.2.17) for terminals in a
network (so I removed everything they don't need from the kernel except
the network stuff, etc.) I compiled them on my laptop b/c it's a lot
faster. Anyway I did the following after I made the configuration with
menuconfig:
'make dep && make clean && make bzImage && make modules && make
modules_install'
Well then I moved the kernels to these machines and everything worked
out fine!!  But now, when I boot the original kernel on my laptop I get
these errors while booting:

depmod: *** unresolved symbols in /lib/modules/2.2.17/net/ppp.o
depmod: *** unresolved symbols in /lib/modules/2.2.17/net/dummy.o
...
now I can't use my modem using ppp anymore b/c when I start 'pon' I get
this:

ioctl(TIOCSETD(PPP)): Invalid argument(22)
/usr/sbin/pppd: This system lacks kernel support for PPP. This could be
because
the PPP kernel module could not be loaded, or because PPP was not
included in the kernel configuration. If PPP was included as a
module, try '/sbin/modprobe -v ppp'

-->'modprobe -v ppp' fails too.

I don't know why this is happening b/c everything was working fine
before I started compiling kernels.
I don't know if 'make modules_install' is the cause for this but I guess
it is.
(I don't have a lot of experience in compiling kernels)

Can anybody tell what causes this and how I can avoid this in the
future?

TIA
Philipp