18 Jun, 2014
Old Logitech mice (and other manufacturers too) sometimes develop the "click of death". Mouse clicks are sometimes not registered, or more common, register as a double click.
This is caused by a worn out micro switch. For my Logitech M505, a Omron D2FC-F-7N, rated for about five million clicks.
New micro switches can be bought on Ebay for about 7 SEK (1 USD) and replacing it is very easy if you have a little experience soldering.