I've been doing a little eyeball research on this. It appears this is only happening with Window 7 64bit clients. I've seen the kix32.exe file listed in the open files on both Server 2003 DC, and Server 2008 DC, with kix32.exe versions 4.53 and 4.61.

Here are my results so far:

                  Server 2008  Server 2003
Windows 7 x64        Open         Open
Windows 7 x32         OK           OK
Windows Vista x64                  OK
Windows Vista x32
Windows XP x32        OK           OK


I have access to Vista x32 with Server 2003, but it will be a week or so before I can test it. If anyone has the other environments, please post your results.