Net Logon Dialog Box freezes on new Compaq XP SP1 box

[wildswing]

I've run into a problem with how a new XP Pro sp1 computer handles DDE or better said, the network password dialog box that comes from being logged on with a user name that's unfamiliar to the remote computer. I've set up an excel spreadsheet on each of 2 computers. The new box is an XP Pro SP1 machine and the older is an NT4 SP6 (The XP box is meant to replace the NT box). I'm trying to transfer some info from one spreadsheet to the other via DDE. It works fine as long as I'm logged on to the XP box with a username that's familliar to the remote NT machine. Both talk back and forth without a problem.

Now, if I change my username on the XP box to something that the NT machine does not recognize, I expect to see a standard Windows network password dialog box come up asking for my username and password. Instead, I see only a title bar. It's as if the network logon dialog box is somehow freezing up and does not completely appear. Task manager does not show the pc as busy and there's lotsa memory available. I've now tried this on 2 new Compaq computers. The first was a small form factor box, and the new one is a mini tower with a 128 Mb ATI video card. Both PCs were 3.0 Ghz, 256 Mb, XP Pro sp1 machines so horsepower and memory should not be an issue. Any ideas?

FYI...the new XP box is meant to replace the old NT machine as a Wonderware Intouch HMI development station.