You've likely used the wrong file for your installation. There is a
complete and a
small distribution file available but you must use the larger
complete one or you will be missing critical files. The smaller one is only for doing updates.
So use file
g1x-101a-1.5.0-5451-full.zip not
g1x-101a-1.5.0-5451.zip Edit : you might also have not completely expanded the distribution file
g1x-101a-1.5.0-5451-full.zip onto your SD card with the folder structure intact.
Finally, ACID is not really an installation utility - it just tells you what firmware version your camera has. Try
STICK or
CHIMP. They will do the installation correctly and also setup your SD card to "autoboot" CHDK each time the camera starts. Using the 'firmware update' method quickly becomes tiring. You might also want to look at this CHDK wikia page
Prepare your SD card .