Poweredge 2950 II OMSA 6.50 issues

I have a PE2950 II running 2K8R2 on which Dell Open Manage Server Admin 6.50 was installed. I recently upgraded OMSA to v.7.4 but discovered  that 7.4 does not support PERC4e/DC adaptors, so I uninstalled 7.4 and did a new install of OMSA 6.5.0.

Following this, OMSA will open, but will not displaye any of the hardware attributes - the basic SYSTEM/MAIN CHASSIS - SOFTWARE/OS and STORAGE menu "folders" are displayed, but with the exception of OS they have no content or subcategories.

I am running OMSA on many other 2950's and 1950's - all on W2K8R with no problems.

The 2950 in question has had its ESM firmware reloaded at least twice but that didn't help - there are no untoward BMC failure alarms during POST.

Any ideas on how to get OMSA 6.5.0. running properly on this 2950 will be warmly welcomed!

thanks / Adrian