Hi Doug,
I have had this problem on two different machines, one CS5 and one CS5.5
The CS5 issue is still a problem, but on the CS5.5 machine I uninstalled a DMXZone Extension I had and the WA Sort behaviour then worked!
Go figure! :-)
Have you tried uninstalling and reinstalling the Data Assist extension? Are you running the latest version?
Cheers
Ian