I'm not 100% unshakably certain on this, but I'm pretty sure that X (xfree86, xwindowing system, xwindows, etc) does not control your fstab file - the one that sets the permissions for the cdrom, the floppy, the MS-Windows partitions, etc - so if your having problems with device access, you might like to post the contents of you fstab file here.
Firstly, does X work? i.e. when you boot the computer, do you get a nice GUI login prompt, or do you get a simple command line login prompt?
If at all possible, if you want to upgrade your system to a newer version of Mandy, try making a backup copy of all your important files and then doing a clean install of the new distro (then put back your important files). Many years of Windows 'updating' should give you a healthy mistrust for the word. I know that Linux is like 500% better and more efficient, but 'upgrades' can still cause probs.