We have a grid class which is used on several of our forms. It allows the user to click on the header and the grid will be sorted in the order corresponding to the selected column. Recently on Windows 7 machines the columns unexpectedly change order. We don't know if it is caused by user intervention, type of mouse, or unexpected key stroke combinations. We do nothing programatically that would cause the behaviour. The user has used our application for 5 years but has never had a problem until she moved to a Windows 7 machine.

Has anyone encountered similar behavior? Currently the -movable- property for the column is set to true which has always been the case. For now we are going to set this to false as a short term measure. However, we would like to determine the cause as we will be moving more users to Win7 machines.

Is this theme related?

Thanks in advance for any assistance.