My post Novatel Wireless Merlin U630 on Windows Vista generated quite some feedback like "How did you install the drivers?". So I decided to take the latest and greatest build 5456 and see if I would get it up and running there too. Here is the list of things you need to do:
Obviously, the first thing to do is to insert the card. You will be prompted for driver installation, and it will try to do just that. However, it will only succeed in installing a "Generic Multifunction PC-Card". The two ports (later identified as multifunction device) will fail because it cannot detect the drivers.
Now we have to rectify this problem. Let's go to Device Manager (via Control Panel / Hardware), and right-click on the "Generic Multifunction PC-Card". Choose "Update Driver":

This will magically turn it into the Novatel Wireless UMTS Modem Parent. And this in turn will allow auto-detection of the two ports:

Please note that the secondary port will show up under COM ports, not Modems:

And here things get hairy - as I pointed out, I am using MWConn. The current 0.9 version (as a reminder: at this time, German-only) assumes that the secondary port is above the primary (ie COM4 for primary, COM5 for secondary). However, on one of my laptops (Samsung X20) - the screenshot above - it is exactly the other way around and MWConn cannot cope with that at the moment. The IBM X31 orders the ports nicely right - and as such, UMTS works like a charm!
By the way, use MWConn with administrative rights because it does create network connections:

I will report back on the inverted port problem, the author of MWConn promised to send me an updated version that can deal with this issue. So stay tuned!
Update I got the new version - and I am modifying this blog entry under Windows Vista 5456 using the Merlin U630 in UMTS mode, on the Samsung X20. Now both laptops work! Proof:
