TrueCrypt and OSX Fuse
I run into this type of problem frequently. I use a strict umask (0077) in my shell.  Usually, when brew is done installing, the dynamic libraries will have the same restrictive mask and the software I just installed doesn't work as a different user. Check the permissions on /usr/local/lib/libfuse.2.dylib. It might be accessible only by the brewer, which could explain why TrueCrypt can't find it.

Since HomeBrew symlinks everything, you may have to change the permissions on the symlink itself, and the file to which it is pointing. For the symlink, use the -h option:

chmod -h a+rX /usr/local/lib/libfuse.2.dylib


While you're at it, check to see if other files have the same problems.

Finally, sudo inherits the umask of the sudo-er. If umask is the culprit here, you might want to also check the permissions for the file-system bundle that you copied as an admin. If those are a problem, use

sudo chmod -R a+rX /Library/Filesystems/osxfusefs.fs


Hope this helps.