Working on a SCOM SP1 deployment and authored a new MP. Tested and signed off.
I had added a dynamically populating group for the use of override targets in the new pack. After importing the MP into the Production MG as normal post pack import you check, amongst other things, to see the monitoring views you have set up are displaying correctly (Of course this varies) where I noticed that one of my views that was linked to a dynamic group containing computer class was not displaying anything. First thing I checked was if the Servers in question had a SCOM agent on and were discovered and healthy. Which they were.. Next thing I checked was view group members on the new dynamic group. empty!! Now This should not be the case as the formula was just to look for machine names of which they were in SCOM. I selected edit on the expression just to take a look and double-check, Changed nothing and clicked ok. Clicked view members again and hey presto they had appeared. Now firstly this definitely is not a caching issues as I had been checking on and off for best part of two hours. It would appear that simulating a modification kicks it into life. I do not thing this issue is in R2 but I will test when I get chance.
I had started looking at the Group Calculation Discovery rule to see how frequent it runs and look for ways to troubleshoot group population but will do another day when i have more time 🙂
So something to watch out for.