Curious problem – I kept getting an error message “Internet Explorer has encountered a problem and needs to close. We are sorry for the inconvenience.” whenever I tried to open a document from our internal MOSS system. Strange.

Eventually figured it out from Geekette’s Blogette, and kbAlertz 833714.

We use Project 2003 still. This means two version of the owssupp.dll, apparently, under c:program filesMicrosoft Officeoffice11 and office12

I followed the advice from the MS Knowledgebase article, but got the same error as all the folks at kbAlertz. In the end I tried just uninstalling MS Project Professional 2003 support – and low, Internet Explorer started letting me open documents from MOSS again. And, much to my surprise, Project 2003 web access works just fine – I guess it doesn’t use that dll.