I can't be sure when this first started happening ....probably within the last month. For no apparent reason I'm unable to use sliders in develop mode. The image in the Navigator doesn't correspond with the main image I'm working on. All tools behave erratically.....Driving me up the wall.
I had this problem a few weeks ago and decided to do an online chat ........I was advised to dump the preferences....It worked for a bit....and now here I am again. Not good. It's not a hardware issue.........and I have 12GB ofRAM installed on my Mac........Anybody help....please?
Here's a guess ... try detaching all external devices (except mouse keyboard and hard drives), such as tablets, phones, track pens, USB coffee makers, etc.