I have an Imac which i have been running on 10.6 for ages and was fine but I just upgraded to 10.9.1.
It was working fine for a week and now my mouse either moves with incredible slowness and short steps requiring multiple swipes to get the cursor across the screen, or it will go quite fast and have the cursor far from where I intended.
My mouse is a wireless optical mouse but I tried a wired optical mouse and there was no change. Is it something in the OSX? or have my mouse drivers betrayed me or something?
If anybody can help it would be greatly appreciated, It is becoming increasingly irritating and difficult to use.