I have been using my MBP (13" mid-2009 running OSX 10.9.5) in clamshell mode with an external monitor connected via minidisplay port, Apple wireless keyboard, and magic mouse for a couple of months. Starting a few weeks ago the mouse would not recognize left clicks anymore and remain stuck on a random spot on the screen with a left click when I close the MBP and try to work in clamshell mode. It still tracks, so that when I move the mouse it highlights from where it got stuck. Also right clicks still work; but obviously they are no use without being able to left click. Also, the keyboard works without any issues.
This problem disappears when I open the lid minimally without waking the MBP monitor. This workaround was suggested here. Similar fixes that people have suggested such as removing any plugged-in USB devices do not apply because there isn't anything plugged in besides the MDP and the magsafe connector.
Additionally, I believe that it's not a hardware issue because it worked previously, i.e. an external bluetooth dongle or wrapping aluminum foil around the MDP should not be required.
Any suggestions or fixes?
Thanks!
Best Answer
News Flash edit
Found this discussion which strongly suggests it is a hardware problem but not the mouse itself. One guy solved it by using a USB dongle.
My original answer remains below, un-edited.
end News Flash edit
Never had this problem w/ my magic mouse, nonetheless...
Get back to a default - disable any 3rd party enhancement software. Reset mouse system preferences to defaults.
Magic Mouse iFixIt video search
From there, Here's an interesting video: Can I DYI fix a Broken Left-Click Resistance?. The tear down may not be something you want to do. I think I would try because the mouse seems pretty useless in its current state. iFixIt sells tools and parts for doing this kind of stuff.
P.S. I liked my magic mouse perfectly fine. In the PC world this thing is E.T. alien technology. Anyway, I like using the magic trackpad much more.