http://bugs.winehq.org/show_bug.cgi?id=31151
--- Comment #12 from Rosanne DiMesio dimesio@earthlink.net 2012-07-08 06:32:43 CDT --- You should have marked the other bug as fixed. I've done that for you.
IE7 was suggested as a possible workaround. From what you say it just made things worse, but problems caused by using native dlls are not Wine bugs.
The priority of "normal" is correct for this bug. http://bugs.winehq.org/page.cgi?id=fields.html#importance
The AppDB has reports indicating that the IERenderer crashes Pegasus Mail, though no one seems to have filed a bug for that. They also state that the alternative BearHTML renderer works; try that in a clean wineprefix.