Huh - should work just fine - did you update the schema on 2009.1 to 99? Not sure what version 6.4 requires but always a good idea on NSM.
I will be having an office day tomorrow. If you don't get it resolved send me a P.M. and I can poke around a little when I can actually touch all my boxes.
Figured it out
Whilst the management port was not plugged in, it was enabled in the config (!). Disabled it and it's now working.