Attached you can find a patch that seems to work better with kernel-package.
Hope this helps. Regards Harri
--- Makefile~ 2007-11-07 16:52:41.000000000 +0100
+++ Makefile 2007-11-07 16:56:20.000000000 +0100
@@ -13,7 +13,11 @@
else
+ifdef KSRC
+ KERNELDIR ?= ${KSRC}
+else
KERNELDIR ?= /lib/modules/$(KVERS)/build
+endif
PWD := $(shell pwd)
default: modules
