Can't install Linux Headers on Debian 6

Question

I don't understand why this isn't working (I'm stumped!);

root@box:/home/user# apt-get install linux-headers-2.6.32-5-686
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 linux-headers-2.6.32-5-686 : Depends: gcc-4.3 but it is not going to be installed
E: Broken packages

root@box:/home/user# gcc --version
gcc (Debian 4.7.2-5) 4.7.2
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

root@node1:/home/user# uname -a
Linux node1 2.6.32-5-686 #1 SMP Sun May 6 04:01:19 UTC 2012 i686 GNU/Linux
root@node1:/home/user# cat /etc/issue
Debian GNU/Linux 6.0 \n \l

Nothing I do will get either gcc-4.3 to install or linux-headers to install. I'm open to any and all ideas.

UPDATE

root@box:/home/user# apt-cache policy gcc
apt-cache policy gcc
gcc:
  Installed: 4:4.7.2-1
  Candidate: 4:4.7.2-1
  Version table:
 *** 4:4.7.2-1 0
        100 /var/lib/dpkg/status
     4:4.4.5-1 0
        500 http://ftp.uk.debian.org/debian/ squeeze/main i386 Packages

Answer 1

It seems as if you have a non-standard set of packages on your machine. The version of gcc you have installed is from the testing repo. As the change of dependencies from gcc can be quite long, there are probably many other packages on your machine that come from testing.

There are a few things you could try:

1. Downgrade gcc. This could be unpleasant due to likely dependencies.
2. Make sure you're trying to install linux-headers for the version of the kernel installed (check with dpkg -l linux-base).
3. Be less specific about the version you're requesting. You might try linux-headers-2.6-686 instead.