Hello,
Thank you for submitting your query with ComponentArt forum.
According to the description provided by you I have tried to replicate the behavior in a sample application with latest build version i.e. 2012.1.1016 however unable to do so. In the sample I have used client mode with a checkbox column header. On running the sample application in IE9, Safari5.1, Firefox 10 and Google Chrome 16; I have observed that the sample is working fine. I have created a video to demonstrate you what I am getting at my end. Please test the sample application and let me know if I am missing anything. Can you determine what I'm doing differently than you are based on this to get the different result, or do you get the same result with my code?
Hope it will help you.
Thank you.
Ajay Mishra