Google Gears can't install - says it's already installed.

[JamesR404]

I've got an issue where Google Gears is or is not installed....

It's not in the list of installed applications nor can I use it, but
if I try to install it it says it's already installed.

This happened after recently upgrading to Chrome 12.0.742.53 beta-m,
then I couldn't use Google Gears anymore and I wanted to use it
because of Remember The Milk, so I went to downgrade my browser to
Chrome 11.0.696.68.

Then when starting it it said it had a newer profile it couldn't read
because the profile was from a newer version of Chrome, so I deleted
the profile and restarted Chrome. No more errors, but also still no
Gears....

How shall I go about getting Google Gears running again? Where is it
looking when it says it's already installed? (i.e. how can I delete
it?)