Ive altered the card in HXD to bootdisk at 00001EO.
You only need to do that if you are trying to setup your card for "SD lock" autobooting. And the G12 was released in 2010 so that is the wrong address to set to BOOTDISK. It won't matter if you are using the "firmware update" method though - its ignored either way.
BOOTDISK (capitals) FAT32 4GB
Good. Be aware that the G12 was released in 2010 so it will not autoboot via the "SD Card Lock" method unless the card is formatted FAT16.
Curiously i never did the '' lock " method previously it it worked ok before
The "lock" method is really handy - CHDK loads every time the camera starts. But if you were using the firmware udpate method, that's fine too. Just a little more work each time the camera starts. (Okay .. a lot more work ..)
When i turn on cam with replay button and press menu i cant get the firmware selection... And i dont get the CHDK flash logo either
There needs to be a CHDK ps.fi2 file in the root of the SD card for the firmware update method to work.
Are you using a Mac ? Like every Apple product, Mac's cause people problems but they buy them anyway. Here's the secret to making a Mac "just work" like all the Mac fanboys pretend it does :
http://chdk.wikia.com/wiki/FAQ/Mac#You_may_have_issues_with_permissions.What should my CHDK files be ? read only? archive?
You should just extract from the zip file to the card. No changes required.