I can't use my Google Account password to bypass the lock screen On my CM9 / ICS 4.0 phone, if I incorrectly enter the drawn pattern five times in a row, it locks itself for 30 seconds. I can't enter any more passwords, but I can click a "forgot my password" button and enter my Google Account password.

On my rooted 4.0.3 tablet running a custom ROM, my lock screen is set with a numeric PIN. If I input it incorrectly five times or more, it locks itself and I can't enter any more passwords. 

I'm not offered the option to enter my google account password to bypass this, although I have configured a Google account on the device.

I want to activate the "I forgot" button in order to enter my Google Account credentials. Is it possible?
It will not show if gapps aren't installed on the tablet (some more obscure brands don't come with gapps).

If gapps are installed, then try and enter it incorrectly 20+ times. This will lock you out. You will only see the enter google details screen if the device has gapps (Google Play, Gmail etc).