Is the background process doing anything with the Outlook object model?
Outlook is designed so that all accesses to the object model must be on the
main thread and especially with VB 6 if a background thread calls into the
object model that will crash Outlook (more with Outlook 2007) or hang it
(more with Outlook 2003 or earlier). Could something like that be the
problem?

I do a lot of background processing with many of my addins and haven't see
the hang problem you describe unless the object model is being used there.

I have seen and heard of quite a few hang problems with Outlook 2007 related
to working with the object model even on the main thread when typing in the
body of an email. What I haven't see are any clean repros (that sort of
thing never yet has happened here on any of my Office 2007 setups for
example) or good explanations of why it's happening.

Some theories are that too many RSS feeds can be implicated, background
indexing of Outlook items for WDS is another possibility, as is a setting
for doing send/receives with too short an interval.

I've had reports from members of the Outlook product group that the same
thing has happened with them with no addins running, so while this may not
help it may not be the fault of your addin at all.

--
Ken Slovak
[MVP - Outlook]
http://www.slovaktech.com
Author: Professional Programming Outlook 2007.
Reminder Manager, Extended Reminders, Attachment Options.
http://www.slovaktech.com/products.htm


"Mark McGinty" wrote in message
...
Our VB6 AddIn uses timers on an invisible form to drive background
processing -- a good deal of which involves MSXML.XMLHttpRequest, called
asynchronously.

The background processing itself doesn't cause any problems, I have had a
virtual running for days with a very short interval for background tasks,
and with multiple inspectors left open -- it has yet to hang. On an
identical virtual, while typing in an email body as I normaly do when
composing, I have seen Outlook hang numerous times. For all occurrences,
background processing was underway when it hung.

Google returns countless reports of a similar nature, but I have yet to
see mention of a solution, nor even an exact cause.

Has anyone else seen anything similar? If so, any resolution? I keep
seeing statements by various MVPs about "compatible" AddIns (some even
suggest using only AddIns developed by Microsoft -- which is pure BS if
you ask me.) Is there any spec for Outlook 2007 AddIn compatibility? Any
idea what the 2007 email editor is doing that is so intolerant of AddIns
doing things behind the scenes?


TIA,
Mark

btw, yes this is somewhat a repost of an earlier question, I wanted the
subject to more accurately reflect the problem.