do you have a debian or custom kernel?
On my system the custom kernel sources are located at /usr/src/linux-2.6.7. I unpacked the modules into /usr/src and they compiled without problems. I have installed the following kernel-related packages:
siim@tibu:/etc/cups$ dpkg --list 'kernel*'
ii kernel-image-2.4.27-1 2.4.27-2 Linux kernel image for version 2.4.27 on 386
ii kernel-image-2.6.7-xt 20040913 Linux kernel binary image for version 2.6.7-xtops5.
ii kernel-patch-scripts 0.99.35 Scripts to help dealing with packaged kernel patches
ii kernel-pcmcia-modules 2.4.27-2 Mainstream PCMCIA modules 2.4.27 on 386
ii linux-kernel-headers 2.5.999-test7-bk-17 Linux Kernel Headers for development
stdarg.h is located at
siim@tibu:/etc/cups$ locate stdarg.h
I guess it is a part of gcc installation, perhaps there is something wrong with your gcc? Are you able to compile something else? There are several version.h-s around here:
siim@tibu:/etc/cups$ locate /version.h
It seems that all of them are kernel related.
Perhaps it helps.