This is an issue I have run into as well

[plesko <plesko@sourcefire.com>]

If you have updated your debian unstable in the last 3 days (since the 21st) there are packages that cause breakage.  I am ABSOLUTELY postive of this.  

A) I am not a linux noob

B) I have installed vmware-any-any-110 patch and this does not resolve the problem. That patch is if you have installed kernel 2.6.20 or greater it fixes a header file.

C) This issue does not have to do with the kernel specifically, as I ran into the exact same issue after I had decided to compile my own 2.6.20 and 2.6.21 kernels.  Neither worked, and even when I reverted to kernel 2.6.18 I can no longer use the compiled module from vmware-config.pl  

I am almost certain it has to do with one of the following unstable packages:

locales_2.5-8_all.deb
libobjc1_1%3a4.1.2-8_i386.deb
libstdc++6-4.1-dev_4.1.2-8_i386.deb
gcc-4.1-base_4.1.2-8_i386.deb
gcc-4.1_4.1.2-8_i386.deb
g++-4.1_4.1.2-8_i386.deb
cpp-4.1_4.1.2-8_i386.deb
libc6-i686_2.5-8_i386.deb
libc6-dev_2.5-8_i386.deb
libc6_2.5-8_i386.deb

I had to reinstall my entire box because I lost the kernel modules I had originally compiled that worked, and then was unable to recompile modules that would not return a "Segmentation fault"