Hello,
The reason I mentioned the PMImport version: Altiris updates this resource every patch cycle (and sometimes "out of cycle", as well). The "out-of-cycle' releases often addresses reporting issues, like yours.
I searched the Altiris Knowledgebase (KB.Altiris.Com) with the keywords: PMImport MS08-052
and found the following articles:
PMImport 6.2.1234.1 (23 September 2008) - Article ID 43779:
https://kb.altiris.com/article.asp?article=43779&p=1
PMImport 6.2.1237.0 (12 November 2008) - Article ID 44394:
https://kb.altiris.com/article.asp?article=44394&p=1
Supplementary PMImport 6.2.1246.2 (12 March 2009) - Article ID 46044:
https://kb.altiris.com/article.asp?article=46044&p=1
PMImport 6.2.1247.0 (10 March 2009) - Article ID 46022:
https://kb.altiris.com/article.asp?article=46022&p=1
Another interesting read for Altiris Patch Management:
List of 6.x PMImport.cab file versions and release dates - Article ID 21897:
https://kb.altiris.com/article.asp?article=21897&p=1
You mentioned you used the Altiris Agent Diagnositcs tool. Did you see any errors in the Agent logs?
Perhaps, the logs may nail down the possible culprit(s).
