Cannot change out of tabbed mode

I learned from reading the manual that tabbed mode is not the only mode that TKabber supports. So, I tried to change it by adding the following like to C:\Program Files\Tkabber\.tkabber\config.tcl:

set usetabbar 0

It is the first line in config.tcl but I see no difference in how the program works. I'm using Tkabber pack 0.9.7 on the download page on Windows XP as administrator.

Thanks,
~David