Bluetooth Mouse Problem

[kamai]

A couple of days ago I bought a Microsoft Bluetooth Notebook Mouse 5000 to use with my Nexus.  I used the process to pair the mouse with the tablet and everything worked fine.  Since then, however, the two items have only talked to each other once in about ten times of trying and I can't find a reason why.
The Nexus Bluetooth screen tells me "Only visible to paired devices", it then lists my mouse 'Microsoft Bluetooth Notebook Mouse 5000' as a paired device.  The mouse, for its part, flashes red and green as the very limited instruction leaflet says it should -- but the two devices aren't talking to each other.
What am I doing wrong?  Would greatly appreciate advice.
 

[Tiny]

The first thing I would try is unpair the mouse.  Then reset and pair again.

[kamai]

Thanks for the tip, Tiny.  It got my N7 talking to my mouse again.
Regrettably, every time I turn off the mouse or the tablet I lose the connection and have to unpair and re-pair next time I want to use Bluetooth.  It seems to me that Google need to have a look at their coding.
But thanks again for your help -- it solved my problem.