Hi,

"I forgot to ask one last thing. Do I have to unregister my old mtdll on the web server and then register the updated mldll on the web server?"

nope.

"And... do I have to redo COM+ each time there is an update to the mtdll?"

i'm not that deep into COM+, but having set up a simple COM+ application, it seems you'll have to "reinstall" the componont to the COM+ application everytime you make changes to your interface.

Regards
Christian