my main problem is this, i open photoshop cs4 extended and begin to work, if i open up another application and use expose on my imac and i go back to photoshop weird things start to happen for example if i use the type tool you cant see anything at all if im typing only the little flashing cursor moving, if i use a any other tool its the same thing, its as if it doesnt work but it does, any new changes i make to a picture or whatever im working on in PS it doesnt update the new changes, to visually see what im actually doing i have to resize my window frame and presto! i see whats going on and the new changes iv'e implemented show up, i think the technical term for this is redraw problems, ive done everything i can possibly think of to make this change and nothing helps ever at all, i have a dual core intel 3.06 ghz with 4gig ram and 1 terabyte hard drive with an NVIDIA GeForce 8800 GS 3d card which is 512mb ram, i have the latest updates for PS and run on OSX 10.5.8, photoshop should run very fast and easy and fine on this but no it doesnt, please try and help me out with this as it is a very serious issue which is disrupting the work that i need to do as im a freelance designer, ive tried upping the cache levels in prefrences panel and nothing, upping the amount of ram photoshop can use and still nothing, allowing extra redrw functions and nothin at all works please help!!!