(Magic) Mouse loses focus

[michael_aos]

OS X 10.10.3.

My primary environment has been some sort of Unix workstation since the late 80's. I jumped onto OS X around 1999. I've been very happy with it, through a LOT of hardware changes over the years.

I've been using various copies of the Magic Mouse since 2009. Lately -- probably with 10.10.2, but especially with 10.10.3 -- it looses focus like crazy. It's nearly unusable. I've tried a few different copies, so I don't think the problem is a particular mouse.

I've wound up using an old Apple wired Mighty Mouse when I get especially frustrated. Works OK, but it's not the same.

Is there any hope on the horizon?

2013 MacPro6,1
Devices (Paired, Configured, etc.):
Mac Pro:
Address: D8-30-62-42-D8-DC
Major Type: Peripheral
Minor Type: Mouse
Services: Apple Wireless Mouse
Paired: Yes
Configured: Yes
Connected: Yes
Manufacturer: Apple (0x3, 0x31C)
Battery Level: 100%
Firmware Version: 0x0084
Vendor ID: 0x05AC
Product ID: 0x030D
Class of Device: 0x05 0x20 0x2580
AFH: On
AFH Map: 1F0000000FF7F
RSSI: -67
Role: Master
Connection Mode: Sniff Mode
Interval: 11.25 ms
Host Connectable: Yes
EDR Supported: No
eSCO Supported: No
SSP Supported: No

 

[rbart]

Mouse lags are a very common issue since Yosemite.
I have only found one working solution:
On all your accounts, disable Handoff feauture (Settings->General) and reboot.

It works for a lot of people, but you can't use Handoff anymore to continue your mail from your iPhone to your Mac ...
I have opened a case at Apple Care to show them, they told me they wasn't aware....

 

[Packdude]

Can you explain what you mean by 'loses focus'?