Make sure you save your Photoshop Workspace, then close photoshop. Re-start up Photoshop and immediately, and I mean immediately, hold down the Ctrl-Alt-Shift keys simultaneously. this will launch Photoshop ignoring it's preferences file. Now reload your Workspace and now try to print. This often solves sudden Photoshop problems as the Adobe preference file is very prone to corruption. If that doesn't work, you may have to reinstall PS and/or your print driver.