The Altiris Service (AeXSvc.exe) is using a large amount of memory and CPU utilization was high also. Upgrading to RU2 didn't resolve the issue.
Confirmed that the Sym Agent and sub-agents did update on the Notification Server and Task Servers.
ITMS 8.6 RU2
This issue is resolved by applying the non-cumulative update "SMP_8_6_POST_RU2_NC_v2_02May.zip" found in the following KB:
235538 CUMULATIVE POST ITMS 8.6 RU2 POINT FIXES