Several folks at WebmasterWorld have reported an issue when using Microsoft's adCenter product. The issue they reported was that when they change a bid and hit the save button, an error message is returned, saying;
Microsoft AdCenter cannot process your request. Please try again. If the error continues please contact MSN adcenter support.
Official adCenter411 Microsoft representative confirmed the issue last night and said that "they're (Microsoft tech team) working to resolve it. I don't have an ETA yet but I will keep you posted as I learn more."
Forum discussion at WebmasterWorld.