Windows 7 64bit and a crashing Citrix XenApp Client

We're starting to use Windows 7 64bit for Developer Desktops (well, three of us so far that are willing to be early adopters).

One of the things we had a problem with was logging into a Citrix remote-desktop; it would give the user a "CDViewer has stopped working". Here are the diagnostics:

Problem signature:

  Problem Event Name:                        CLR20r3
  Problem Signature 01:                       cdviewer.exe
  Problem Signature 02:                       11.2.0.31560
  Problem Signature 03:                       4aac18be
  Problem Signature 04:                       DesktopViewer
  Problem Signature 05:                       11.2.0.31560
  Problem Signature 06:                       4aac18ba
  Problem Signature 07:                       105
  Problem Signature 08:                       80
  Problem Signature 09:                       System.IO.InvalidDataException
  OS Version:                                          6.1.7600.2.0.0.256.48
  Locale ID:                                             1033

It has something to do with the version of Citrix that we're using on the server vs. the latest client version. The workaround is rather simple, in Windows 7 you need to associate the ".ica" extension with C:\Program Files (x86)\Citrix\ICA Client\wfica32.exe program.