after an upgrade of our mom servers and agents, we noticed that any of our performance threshold rules were bringing back empty values in the "description:" field. as you'll notice from the snippet below, the information does exist. for example, source contains "smtp server" and "remote queue length", both of which should be filled in for the description.
Description: : : value = Name: SMTP: Remote Queue > 250 Severity: Error Source: SMTP Server: Remote Queue Length: _Total
if you're running into this problem, it most likely stems from a deployment of hotfix kb934441. kb934441 upgrades the momengine.dll component to 5.0.2911.41 which is the source of the issue. there's an unpublished hotfix for this known issue that corrects this problem. you'll know you're running it if your version number is at 5.0.2911.42. you'll need to call microsoft if you're experiencing this problem. here's the .msi name to reference: MOM2005-SP1-KB942736-X86-IA64-ENU.msi.