Every time I boot up my Mac it does not find my magic mouse

When I boot up my Imac with Lion, it does launches the Bluetooth connection wizzard.

I have to lift up my mouse, and see the green light, and then it connects.

Battery level looks normal, at least I do not get a signal saying to replace the batteries.

This has been going on for a couple of weeks maybe.

Any idea's how to solve this?