This has the same casue as #81566: the version of realplayer that Potato's installer was designed for has passed into obsolescence. I ran into this last week, when Cally complained that instead of getting her missing episode of old-time radio there was a nasty-dialog saying her player had "expired".
The good news is that Joey Hess has an updated installer. It's been in unstable for a while now, and it appears to work just fine for Potato. (Okay, I grabbed the source and rebuilt it rather than trying to figure out if there might be any link-version problems. So realplayer_8.0-potato1 worked fine, right "out of the box". Thanks, Joey. I would have been asked to wrestle with Windows if I hadn't found the fix for this Real Soon!) I would suggest these bugs should be combined and repaired by a built-for-potato "port" of Joey's package now in unstable... if that hasn't been done since last time I looked, as I've been meaning to come back and follow up on these bugs for a couple days. Where would I file a bug about days being too short? :-) -- WWJD? JWRTFM! -- bumper sticker after a suggestion by TNH