Oh, this is too weird.
TSM 5.5.4.2 server on Win2k3.
Just upgraded the client on the same box from 5.5 to 6.2.2 so we can use 
SNAPDIFF to back up a Netapp.

Installing the 6.2.2 CLIENT disables the SERVER.
Yep. Didn't think it was possible.
DSMSERV message is ANR8591, "IBM GSKIT V7 must be installed".
Here's the link I found to the hit:
https://www-304.ibm.com/support/docview.wss?uid=swg21442260

But the link it gives for the GSKIT patch doesn't' have an option for a Win2K3 
version.

Commenting COMMETHOD HTTP out in the dsmserv.opt didn't help.
Uninstalling 6.2.2 client reenables the server.
Repeatable.

Anybody else run into this? What was the fix?

wanda, slinking off into stunned silence....