Just to clarify further the situation. MBP works correctly with the correct mouse.
iMac mouse still cannot be picked up by iMac, but the fact that it is OK is proven by its having connected to the MBP and worked fine with it.
I found an old iMAC MIGHTY mouse in the house, put batteries in it, and found that new mouse immediately connected to the iMac without any delay or request. Yet it had never been used on the present HD or OS. That enabled me to work the iMac controls again. But a search on Bluetooth for the other mouse that stood right next to it was unsuccessful.
Why after 2 months should a Mighty Mouse connect to the wrong computer and function perfectly there, but thereafter refuse to function any longer with the original machine? Can anyone here tell me what explains that?
Have had for some 12 hours now a mouse problem. We have two Macs, one a 2006 iMac on leopard, other mBP 2011 on Snow. Started with iMac bluetooth mouse failing to be found on startup. Then I found the MBP was connected to the imac mouse. Bluetooth On in topbar is greyed out but I separated the mouse connection in preferences & selected the right (flat) mouse. Restarted iMac but still no joy. Then found it's mouse had reconnected to MBP. I found BTfilesharing was open (strangely) and ended it. And ended wrong mouse connection. For several hours MBP mouse worked fine, then in a hour absence lost all connection to the flat mouse on return. Attempts to re-establish the connection repeatedly fail on MBP, even though Bluetooth finds the right mouse. It then continues to turn but eventually tells me the connection has failed. Repeatedly. During the period when right mouse worked I put in the latest Mac updates inc. new java.
The iMac is on and up but virtually unusable with no oval Mighty Mouse connection. Batteries are all 100%. Ideas?

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