worked:

drbd8
et131x
fglrx-kernel
ipw3945
kqemu
ndiswrapper
nvidia-kernel
openafs
qc-usb
realtime-lsm
sl-modem
sysprof
tidev

fails to build:

nozomi-source
rt2400-source
rt2500-source
rt2x00-source
rt2570-source
spca5xx-source (include/linux/config.h)
misdn-kernel-source (include/linux/config.h)
madwifi-source (warnings treated as errors)
exmap-modules-source (make: *** /lib/modules/2.6.22-grml/build: No such file or 
directory)
iscsitarget-source (event.c:98: error: too few arguments to function 
'netlink_kernel_create')

problems at grml-kerneladdons-2.6.22-grml - needs some investigation:

WARNING: /lib/modules/2.6.22-grml/misc/pcan.ko needs unknown symbol malloc_sizes
WARNING: /lib/modules/2.6.22-grml/misc/aufs.ko needs unknown symbol 
lookup_one_len_nd
WARNING: /lib/modules/2.6.22-grml/misc/aufs.ko needs unknown symbol malloc_sizes
WARNING: /lib/modules/2.6.22-grml/misc/cowloop.ko needs unknown symbol 
malloc_sizes
WARNING: /lib/modules/2.6.22-grml/misc/snd-bt-sco.ko needs unknown symbol 
malloc_sizes
WARNING: /lib/modules/2.6.22-grml/misc/tpm_emulator.ko needs unknown symbol 
malloc_sizes

todo:

truecrypt-2.6.22-grml