Someone I know has a 20" Intel iMac. He installed Windows XP and Parallels, but now has problems printing anything on his Epson CX5000 all-in-one printer when he's using Windows (with Mac it works - surprise, surprise). So I downloaded the necessary Windows drivers for that printer. He now reports that the printer is recognized (nothing happened before), but he still can't print.

Without having to drive all the way to his place to figure this out for him, what am I missing? That is, what should I try next to solve this issue?