Hu Kitefre
your post is a bit ambiguous. Were you:
1. updating the firmware in your s90 using a firmware update supplied by Canon, or
2. loading CHDK using the 'firmware update' method
If (2), then there should be no problem. Your camera's firmware has not been altered - what CHDK does is use the Canon firmware update mechanism to load CHDK into memory - there's no permanent change to your camera. Just recharge the battery and try again. If it doesn't see to work, make sure you are following the CHDK install instructions properly (see
http://chdk.wikia.com/wiki/CHDK_for_Dummies#Load_CHDK_onto_the_card).
If (1) then you may have a problem that only Canon can fix (though I'm not aware there are any s90 firmware updates).
