Are you getting this error in your event viewer?
Event Type: Error
Event Source: EventSystem
Event Category: (50)
Event ID: 4609
Time: 9:29:41 PM
The COM+ Event System detected a bad return code during its internal processing. HRESULT was 8007041F from line 44 of d:\qxp_slp\com\com1x\src\events\tier1\eventsystemobj.cpp. Please contact Microsoft Product Support Services to report this error.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Here's what was causing mine.
I removed the app and all was well. I have not tried reinstalling because I run MSN Messenger.
How'd I find out? Easy, but time consuming. One-by-one I disabled each startup process found in MSconfig (Start > Run > msconfig) and rebooted after I disabled each event. When I disabled msmsgs, this error stopped. Keep in mind however that this error takes some time to show up. It occurs at the end of the startup process, so give your system plenty of time to boot up and stabilize before you look in Event viewer log.
The interesting thing is I found this while trying to determine the answer to another puzzle. McAfee Antivirus' On-Access Scan was getting disabled by itself! I found nothing on the web that helped solve this. I did find this. It didin't help me because I was already running version 8, but it did lead me to look at my Event Viewer (Start > Control Panel > Administrative Tools > Event Viewer > Application). I found the above error in the Event Viewer > Application log and decided to start disabling startup processes to find the culprit. As soon as I uninstalled Windows Messenger, McAfee On-access scan remained enabled! Yea!!