bt mouse

I'm new to the mac world although my question really isn't all that related to being a n00b. I have a BT Intellimouse that works great with my imac but sometimes when I bring it out of sleep mode (pressing a button on the mouse or the space bar) it is no longer paired with my mac. Is it normal to have to push the connect button under the mouse? I also notice then when I come out of sleep mode the first thing I see is my screensaver even though I put it in sleep mode. Any help would be great. So maybe I am a n00b.

I've never had that problem with any other BT mice, but I've never had that mouse.