Your only hope is if someone with another 3750 gets it working. You can then compare configuration and see what is missing.Sorry I can't help any more.
Looks like Cisco might be leading us along the garden path. Version 12.2(20) doesn't seem to allow the Network Assistant to connect (even though is says it does). The NO SHUT refers to the management VLAN which is normally VLAN1.I have just upgraded ...
I believe that the minimum version is 12.2(20)EWA .I have that version but the problem is still the same.The only clue is one line on the Cisco website about setting SVI interface to NO SHUT .Have been unable to find out how to configure.