Hey All,
Just discovered (by accident) a new blog about DPM. The name of the blog is DPMCallBack and can be found here: http://blogs.technet.com/b/dpmcallback/
The first post is already a good one so I’m hoping for more 
The post describes the questions that you will get when you have issues with your DPM installation. Whenever you want to open a case for DPM, it is good to have these questions answered in advance, it will save you some time 
Here is a copy of the questions:
• Is this a fresh installation of DPM using the RTM bits or was this an upgrade from a previous version or from Beta?
• When did the problem first start? You can select the Monitoring tab and review the Alerts/Jobs for details.
• Has it ever worked as expected?
• What changes (if any) were made just prior to the failures?
• Can you reproduce the problem? If so can you please provide the exact steps?
• Are other protected data sources experiencing the same problem?
• Is the error specific to one type of data source? Example, Exchange jobs fail but SQL and SharePoint are successful.
• What is the application version that is experiencing the problem? Example, SQL 2005, SQL 2008, Exchange 2007…etc.
• Is the protected data source running on a standalone server, domain controller or a cluster?
• Is the system that is experiencing the problem in the same domain as the DPM server?
• Do other protected data sources reside on the same machine? Are they also failing?
• Is the target machine for which you’re experiencing the issue on the same LAN as the DPM server or over a WAN?
• What is the error message and ID in the Details pane? If possible, please copy/paste this or provide a screenshot.
Cheers
Mike