NIS 2011 with Airport Utility on Win7 x64

I have upgraded NIS from 2010 to 2011 on Windows 7 x64.  With Apple's Airport Utility 5.5.1, when I click either "Manual Setup" or "Continue" from the main panel with my Time Capsule selected in the left pane, I get "An error occurred while trying to access the Apple wireless device. Make sure your network connection is valid and try again.  Error 10057".  I can still get to the configuration dialogue, but only by doing File-->Configure Other from the menu bar.  This error has only appeared since the upgrade of NIS to 2011.  I have also upgraded NIS on two other computers, one XP Home and one XP Pro, and the issue does not happen on those computers - Airport Utility is still working as it did before.  NIS product settings were preserved during the upgrade.  It's not a big deal, just slightly inconvenient, but I'm curious about what's happened, and wonder if anyone can shed any light on this.

Regards,

 Lindsay.