Many thanks for the guide. I must bookmark it as I depend on it every time a new kernel update is released and then spend a while wondering why truecrypt doesn't work.

A couple of tips for anyone struggling...

For the 2.6.23 kernel I had to use the following to get the source rpm...

rpm -ivh http://www.mirrorservice.org/sites/download.fedora.redhat.com/pub/fedora/linux/updates/7/SRPMS/kernel-2.6.23.1-10.fc7.src.rpm

Also the 4.3a source doesn't compile against 2.6.23, but someone has posted a patch here...

http://andika-lives-here.blogspot.com/2007/10/truecrypt-43a-patch-for-kernel-2623-rcx.html

For those not up on patching (like me), I just copied the patch text down to the end of the last line and pasted it into a file (e.g. patch-2.6.23) and put that in the kernel directory under the truecrypt linux source, then ran 'patch -l -p0 < patch-2.6.23' from that directory.

Seemed to build then.

Phew. Whilst linux is certainly getting there with usability there are still a few little things like this which requires getting dirty. Really shouldn't have to mess about with kernel stuff, but anyway. What we really need is a truecrypt fedora package on livna or somewhere similar (any idea how you go about requesting that?).