"connection lost" VERY frequently with mighty mouse

I had the same problem with my mouse, but got it fixed!

The REAL CULPRIT IS BATTERIES! The solution is get the right batteries! This mean even if you replace new batteries you may face the same problem, if the new batteries doesn't suit, it may work for short while then the problem will come back again...this happened to my mouse. At first, I was totally disregard the fact that batteries create the problem because it works fine when i replace a new one, it only went off days or weeks later.

Now I am using the yellow batteries from ikea, no issue since using them.

Why? This is because the yellow wrap on ikea's battery is thinner hence you get longer tip (nipple) protruding out on the battery hence it's able to reach the contact surface inside the mouse, as you may notice the contact surface of the mouse is deep inside a hole...if you don't have ikea's batteries, other batteries with thinner wrapper or longer nipples will do 😉, worst scenario, you can add few layers of aluminium foil on the nipples to extend the reach 😉!

Good Luck!

I've had the same problem as the original reporter (with a new Magic Mouse) since I first put my own (second) set of batteries into the mouse - the first pair that came in the box gave me no trouble until they reached end of life.

This second set I'm using now are Duracell Plus AA cells. Battery levels are claimed to be ok, and putting in a brand new third and fourth set makes no difference. (Just had 'Connection Lost' for the umpteenth time this evening! To get things going again, click rapidly until the mouse reconnects; give it a chance, as it doesn't happen immediately.) I've had my Apple Wireless keyboard and the Mighty Mouse set as Bluetooth 'Favourites' as recommended by Barry Hemphill (see above in thread). Resetting PRAM, SMC, 'fixing permissions', throwing salt over my shoulder, getting a black cat to run in front of me etc all useless. No help from Apple's http://support.apple.com/kb/TS3048 "Troubleshooting Wireless Mouse and Keyboard Issues".

Interestingly, the green light under the mouse doesn't go out completely in the error situation, but does a double blink: on, on ... on, on ... on, on - this is 'discovery mode'. More frantic clicking until it works again for another fifteen minutes. It would be a good device if it worked properly.

Perhaps it is the batteries not fitting well, coming loose and causing the mouse to restart? No Ikea near me for the batteries suggested by th3ming - can any UK reader recommend some battery types which work all the time?

I think it is loose battery seating - try putting a piece of folded paper under the lid to snug things up - this may have fixed my issue (too soon to be sure).