If it's a networked printer, you need to read the SP2 release-notes chapter on getting XP to work on a network. There's some minor settings you need to pester.
If it's not a networked printer (ie - it's attached to your PC directly by a serial cable or USB) then you have a few options.
1. Update your printer's drivers.
2. Visit the printer's site for information on compatability with SP2
3. Install a generic printer, directed at your real printer, and then tweak the setup.
4. Check your permissions for the printer.
5. If you still have the printer installed, uninstall it, disconnect it, reboot, then attach it and let Windows find it and load it up. Then patch it with the manufacturer's drivers.