This is taken from my blog but mods won't let me link to it so I will post it here: This came about after buying a Magic Mouse and finding that the mouse wasn't working how it should. The pointer was lagging and the mouse would disconnect are reconnect at random . Taking a look on the net I found lots who have the same problem even with older Mac Pros. There is a fix for the older models which involves swapping antenna wires that go to the bluetooth card. Now I can't verify this but some say the labels on the antenna cables are wrong but it could be that the wire swap fix uses the airport antenna instead of the bluetooth antenna ? So I decided to take a closer look and came to the conclusion that the Mac Pro bluetooth antenna does not work as it should. This could be down to bad placement, bad designed antenna or the metal of the case. Where is the bluetooth antenna ? If you try to follow the bluetooth antenna cable you see it goes behind the motherboard but impossible to follow. I wanted to know so out came my motherboard. You can see from the picture below that is on the right sort of behind the PCI blanks. The antenna is flat, about half inch wide and 3 inch tall. Looks pretty rubbish. Sorry I didn't take any photos. After more research I have found 2 possible fixes both costing about £10. The first and easiest. Buy yourself a usb adaptor plug it in and off you go.. Well not exactly. It seems that 2 bluetooths together aren't so happy. So to fix this you will need to disconnect the original apple bluetooth located on the motherboard . 1: Remove power cable . 2: Remove case cover 3. Remove processor tray. 4. Locate bluetooth card and disconned the small plug on the left hand side. 5. Put back in reverse order. TEST. BLUETOOTH FIX USING ORIGINAL BLUETOOTH CARD I prefer this way as I'm not adding any hardware as such I'm just replacing the antenna. This way no usb ports are being used and you use your original bluetooth card. You will need to buy 2 things. EBAY is your friend. A wifi antenna. As wifi uses the same frequency as bluetooth. A U.FL Mini Pci to RP-SMA CABLE to connect from the bluetooth card to the new antenna. 1: Remove power cable . 2: Remove case cover 3. Remove processor tray. 4. Undo the 2 screws and remove the PCI holder plate 5. Undo the 2 screws for the fan and pull the fan forward. (You need to do this to remove the graphics card.) 6. Push the metal bar on the left side of the graphics card to the left and remove the graphics card. 7.Remove a PCI blank and drill a 6.5mm hole in the middle. 8. Fit the RP-SMA connector and tighten the locking nut. 9. Put a little insulation tape on the other end as we need to fish this behind a support and don't was to short anything on the motherboard. 10. Pass cable behind support and fit the PCI blank into place 11. Disconnect the old antenna.Its a very small plug and you must pull it forward towards you (away from motherboard) and connect the new U.FL cable. Tie up and insulate the old antenna cable to avoid short circuits. 12. Refit all in reverse not forgetting the push the metal bar that holds the graphics card to the right before refitting the fan. 13. Screw new antenna into back. TEST My bluetooth works fine now with my original bluetooth card and new antenna. I have tried it form far away as possible 5-6 metres and works fine. The other thing to do is add your mouse as a favorite in the bluetooth preferences. Your comments are welcome... have a nice day and happy fixing. Remember if it's not broke don't fix it.