Q: iMac losing bluetooth connection to Magic Mouse

Hi guys,

My magic mouse has started to lose connectivity to my iMac.It connects loses the connection for up to a minute sometimes longer. I have to force the bluetooth to connect via the icon in the toolbar but 5 or 10 or 30 minutes later same again. All with new batteries.

So I changed the mouse for another magic mouse from my MacBook air. Same problem but both work perfectly on the mac book air. So it has to be the iMac.

I also have a Apple trackpad connected as well but have done so for a couple of years.

I am on Mavericks with all the latest updates.

I have deleted all mice from the iMac, turned bluetooth off, re booted, re paired and still the same.

Any ideas??