I'll be honest - Finding things on your site is very difficult, so this may have been reported.
I just downloaded and installed System Manager 2.0R1 (why you added the "OnCommand" part simply adds to the Puzzle of your application suite...)
The issue is:
Using FAS2040 running 7.3.3.
System has 13 Volumes/LUN's on the "A" head, 32 Volumes/LUN's on the "B" head.
When I start SM and go to LUNS on the "A" head, scroll down the list to the bottom, then do the same thing on the "B" head, then return to the "A" head, the application has the previously selected last-LUN highlighted in the LUN list, but the scroll-bar on the right side is at the top meaning the list is at the top, not the bottom. The scroll-bar on the right side of the screen needs to sync with the selection list when you return to the screen. This has cause me confusion in several situations. This issue existed in the Beta, and was reported then too.