Thunderbird 0.8 Can't Read Emails Right

I use SuSE 9.1 and Mozilla Thunderbird 0.5. I have almost 1700 emails and don't wan't to lose them. When I upgrade Thunderbird to 0.8 it doesn't read the messages right. It reads them similar to the way they seem from a text editor. Is there a way to export the 'Inbox' file, or am I stuck with Thunderbird 0.5. Version 0.6 and 0.7 had the same problem. I tried various SuSE 9.1 RPMs and the source directly from Mozilla.