Mouse not working correctly

[bigeasy]

Hi All,

 

I've recently installed 10.8.3 on my system and I'm getting some odd behaviour regarding the mouse cursor. 

 

It's hard to explain and I might have to upload a video to demonstrate it fully, but in essence the finder and dock are not responding properly to the mouse cursor. 

 

For example: when I put the cursor over the dock it doesn't expand like it should, it only works if I grab a dock icon and move it around and if I click a docked icon the dock will expand and stay fully expanded until I click elsewhere.

 

Also if I click an option on the finder bar, the apple icon for instance, when i pull the cursor over the menu it doesn't highlight the option or go into a sub menu unless I'm holding the mouse button down.

 

Has anyone else experienced this? And if so is there a workaround?

 

My mouse is correctly identified in system profiler as a rat7.