Thank you for reporting this bug. We will make it our priority to review this report.
Ext GWT Premium Member
[FIXED] [2.0 Trunk] Clicking Column Header of Grouping View selects incorrect column
Steps to reproduce...
1. Open Grouping Example
2. Select column 'Price' as the grouping column
3. Select column 'Change' to sort by that column
4. Column 'Industry' is incorrectly selected/highlighted
Seems to affect columns to the right of the hidden grouping column.
Turning off grouping via the menu or showing the grouping column makes it work as expected.
Fixed in SVN. Let us know if you have any other problems.