You don't give complete version number, but are you trying to upgrade directly from 12.0 to 13.0?
I usually do complete installs when a new distro is released, but the times I have upgraded, I haven't experienced any problems. But remember that there has been two versions in between. So there might be issues upgrading from 12.0 (avoiding 12.1 and 12.2) directly to 13.0 (or 13.1 for that matter).
Last edited by Dinithion; 07-06-2010 at 04:21 AM.