When I try to run it normally, the hangs described by other people occur - working once in about five tries, with a hanging intro screen most of the time. When I run by using WinLauncherXP set to operate on only one CPU of the dual, the numbers are about reversed: one hang for about five loads to the scenario screen. I am able to play the games but have not done so to completion, thus can't be sure how stable it stays. However, gameplay has seemed perfectly normal as far as I can tell.
You should be able to find WinLauncherXP through Google. It is a free windows program that allows you to adjust the number of CPUs used by a program, as well as some of the priorites applicable to that program. There is also a command line based program that does this called xcpu. I have not tried it but it would probably allow one to use batch files on game startup to get the same effect. Both programs are rather old and may not have any support for updates - so stability my be an issue for some.
I would hope this could be corrected in a patch for Campaigns on the Danube, but I don't know the details on it.
Hope this helps someone else.
Dizzypaint