wireless mouse doesn't stay connected

I keep my Macbook plugged into a larger monitor most of the time, but when I do disconnect it and then plug it back into the monitor I lose the connection with my mouse. Sometimes it returns immediately (which I think it should) other times, it takes a minute, but most of the time, it doesn't return at all.

I go into Bluetooth in the preferences and the 'on' box and the 'discoverable' box are both checked, but it says 'mouse not connected' at the left. All I do is uncheck the discoverable box and check it again and it works fine. Pain in the *** though.

Is there something I can do so this thing stays connected all the time and I don't have to go through this each time?

I have a bluetooth mouse as well, and I run into the same random disconnect problem at various times. Not often, but enough I notice. I haven't found a fix to the problem, but I've heard several people complain about bluetooth mice in general.