Motorola PEBL U6

I just bought an unlocked PEBL to use with Cingular. Reception works great as does most everything else but just one bothersome issue. Everytime I go to check my voicemail, I get a wierd text message from what looks like a little wine bottle and the @ symbol. When try to reply, no reply address. I've messed around with the notification settings on both voicemail and message inbox, and this didn't help. I've also spoken with both Motorola and Cingular and they were pretty much useless. I have a friend having the same exact problem with PEBL on T-Mobile (also unlocked). Any help would be greatly appreciated. I've thought about doing a software update but I really don't want to lose all the settings, rings, etc on my phone. Thanks!