Icon "sticks" to cursor in finder
When trying to drag an application icon off the dock the icon "sticks" to the cursor. Also, in finder windows the same phenomenon occurs when I attempt to move an icon to a new location.
Attempted solutions: restart with PRAM clear, reinstall OS X, clear system caches, etc.
No luck so far. Any help appreciated. Thanks.
MacBook Pro, OS X Mountain Lion (10.8.1), Late 2008 Unibody 2.4 Ghz; 4 GB RAM