I can make the change if I am in the SQL view query editor. However, if I make the change in the graphical query design window, then on Save it reverts back to "no function".
Could not confirm this bug with OpenSUSE 12.3 64bit rpm Linux and LO 4.3.0.4. If you have chosen a value or a function you have to lose set the focus to another filed. So the grouping will be accepted. Have a look at Bug68678
This bug exists on the Windows 7 64 bit platform. I tried your instructions and can confirm that your workaround is working. I have to set the value of the function and then step off the field in order to save the change? MS Access doesn't make me do that. May I suggest as a 20 year IT veteran that this would not work for the average user? The suggested functionality should be that if i change the value of the drop down list, then i should be able to save it immediately. I should not have to use a workaround.
I have written down the workaround and the link to the original bug: Bug68678 If the workaround is working, this bug would be a duplicate of the (open) Bug68678. This buggy behavior exists since LO 4.1. I will set this bug as a duplicate. *** This bug has been marked as a duplicate of bug 68678 ***