Note to self (and anyone else who listens):
If you're using MSMQ on your back end, and suddenly, without any reason, you start getting an error like this in your event log:
"An unexpected error was returned by the Message Queuing API MQCreateQueue : The Message Queuing service is not available Server Application ID: {02D4B3F1-FD88-11D1-960D-00805FC79235} Server Application Instance ID: {248330A8-B483-4B3F-88E1-12414BE25062} Server Application Name: System Application Error Code = 0xc00e000b : COM+ Services Internals Information: File: d:\qxp_slp\com\com1x\src\comsv..."
You may have had the misfortune of installing some hotfix from Microsoft which screw around with some of your NTFS permissions, including Queue related ones. After googling around and emailing the whole world, A friend of mine helped me find the fix: Uninstall and then reinstall Message Queuing.
The symptoms I had
were that the Message Queuing Service was running just fine, but the Message Queue Triggers service was set to automatic, but not started, and you couldn't start it if you tried.
Also, If open my computer management console, under applications and services, I couldn't even see the Message Queuing information node!
after the reinstall, the triggers service was set on "started", and I could see message queuing node on the Computer management mmc. All was running fine after that.
And it only took 5 hours to figure out! Arrrrg!