All DPs read "Failed to retrieve the package list on the distribution point"...

Question

About 2 weeks ago all 10 of my DPs started reporting the following warning (roughly 2 weeks after upgrading to R2):
"Failed to retrieve the package list on the distribution point ["Display=\\<server.FQDN>\"]MSWNET:["SMS_SITE=<code>"]\\<server.FQDN>\. Or the package list in content library doesn't match the one in WMI. Review
smsdpmon.log for more information about this failure.
This warning has appeared in my environment once before and I've read a number of posts regarding it. In the previous situation I found the problematic package ID recorded in smsdpmon.log and followed the standard procedure of redistributing and then proceeded
with a validation check on the affected DP. These steps resolved the issue originally.
This time around the package ID is not referenced in smsdpmon.log. It had the same error but the ID was not listed. Unfortunately the logs have already rolled over and I forgot to save a copy so I don't have anything to reference. I'm curious if anyone else
has seen this behavior and what the recommended fix is. 
As always, appreciate the help!

Answer 1

I used the following process to clean up these warnings on my DPs:
Setup content validation checks for each of my affected DPs to run every morning (previously only set to weekends). I did this so when I made a change I could validate whether or not it worked the following day. It would be great if there was a way to force
these checks manually but I haven't found a method yet.
After the content validation check completed I filtered through the smsdpmon.log on each affected DP. This revealed the package ID that was causing the issue.
In my environment the package in question was not needed so I deleted it. If it is required I suspect re-distributing it would work as well.
At this stage the problem was still not fully resolved for me. Even though I had deleted the package WMI was still inaccurate. I used this script to scrub WMI on all affected DPs and it picked up the problematic package ID:
http://gallery.technet.microsoft.com/Powershell-script-to-fix-81dc4e69
My content validation checks are now passing and the warnings are being cleared. YEAH!
As a final note - After running the PS script Nickolaj posted I ran started seeing dozens of error checks on my packages (Distribution Manager failed to process package "Laptop Drivers" (package ID = XYZ00123).) After doing some research
I found I was prone to this issue:
Failed to start DP health monitoring task. In my case the suspect file was called "Microsoft". I moved it to another location and the errors cleared immediately.
Hope this info is helpful to others!