As we all know, the Outlook crawler in Aperture isn't very stable at the moment, probably due to using a COM bridge. Recently, I stumbled upon a relatively new Java library that can read the Outlook PST file directly. I have tested it on Outlook 2003 and 2007 with good results. Would be nice to have this one replace the current Outlook crawler.
Here's a link to the library: http://code.google.com/p/java-libpst/
Tran Nam Quang