Before you buy any mouse especially logitech, check if anyone has previously observed double-clicking issue.
M510 has it. - http://forums.logite...p/591328/page/3
M705 - Not sure but it might have.
I have M905 I got a brand new box packed replacement but after a month it started giving me troubles again.
I tried all the fixes so far except modifying the hardware. It seems logitech has a design flaw maybe.
Check the relevant links, I don't think I would be going for logitech's Mxxx range again.
http://www.experienceit.pl/download - Brilliant software it does work
I must say I do like the M905 and I really wished it didn't have double-click issue. It just makes it unusable.