I have a Canon S5 Is with the "b" firmware.
I've been using allbest-s5is-101b-50.zip for a few days.
Problems occured as I changed options over a few days.
The CHDK histogram never worked. I did shutoff the Canon
histogram, but the CHDK histogram never appeared.
I later adjusted several options such as "shutter volume,"
moving battery icon, moving "storage left" icon. All of
this was done in AUTO mode.
When I went to PROGRAM mode, selecting ALT caused the ALT
icon not to appear, but then pressing the MENU button would
cause the ALT menu to appear without text.
It could be a coincidence, but a blue "hot pixel" suddenly
appeared in the LCD.
So, I deleted the CHDK.GFG file. This put the camera back to
the same point as when I first loaded CHDK.
So, I deleted everything on the card. Then I installed
CHDK-s5is-101b-0.5.5-526autobuild.zip
No matter what I did, the ALT menu did not appear.
Oh, the "hot blue pixel" disappeared.