Annoying grey border on layers & slow performance. Help please

Question

Hi,
My work recently upgraded me to a new Mac and Adobe CS5 (I was using CS3 before). There are a couple of things in Photoshop that seem weird, and slower and laggier, which just doesn't make sense since I'm now using a newer version of PS on a more powerful Mac.
Firstly, I've noticed that when I move layers around with the move tool, a grey border appears around them. I find this very distracting and it looks horrible. It just looks and feels so 'wrong' that I assumed it was a bug, and spent half an hour fiddling with various Photoshop and OS settings trying to get rid of it. But after some Googling, I read somewhere that it's actually a new 'feature' in CS5. Please, please, please tell me there's a way to turn it off (I looked in the preferences but couldn't see a relevant option). Not only is it massively distracting and unnecessary, it's very laggy too: when I move a layer around with the mouse, the grey border struggles to keep up with the content of the layer. It's as if the border isn't redrawn frequently enough per second, and as a result, it kind kind of erratically pops and flickers around my layer as I move it around. This leads me to my next issue.
Certain things, such as moving layers around, are slower than they used to be. If I move a layer with a largish image in it around the screen, the redraw doesn't seem good, and the image flickers and splits as I move it around (this is made worse by the above-mentioned grey border problem). CS3 wasn't this laggy. Also, I've noticed that when I change the colour of things using the colour picker, it doesn't update the screen as quickly as it used to. For example, if I change the "color overlay" settings of a layer, or the colour of a text layer, there's a delay of half a second or so between when I choose a colour on the colour picker and when my image is updated with the new colour. This slight delay quickly becomes very annoying when experimenting with dozens of colours while trying to find the perfect colour for something.
So, my questions are:
-Is there a way to turn that grey layer border off
-Is anyone else finding the redraw performance in CS5 to be subpar? Are there any settings or something I can change to improve it? I don't want super-duper performance. I just want CS5 on a brand new Mac to not feel crappier and laggier than CS3 did on an older, weaker Mac.
My specs:
2x 2.26Ghz Quad-Core Intel Xeon Mac Pro with 14GB RAM
ATI Radeon HD 4870
OS X 10.6.4
Photoshop CS5 (12.0.1 x64)
The above problems relate to big PSD files as well as small, simple PSD files (eg. 1920x1200 pixels with just 3 layers). I've tried enabling/disabling OpenGL and trying different cache levels but that doesn't seem to make a difference.

Answer 1

1 - Thanks, that fixed it. Though if it's a Mac/cocoa problem, then I wonder why I only ever saw the outline in Photoshop? I tried dragging everything that wasn't nailed down in the OS, yet I never found anything that had a grey box displayed around it. Anyway,  glad to be rid of it. I was beginning to think that I would never be able to upgrade from CS3 on my home computer (I'm using CS5 at work only) - the problem was that annoying to me that it was basically a deal-breaker.
2 - Sounded promising, but after installing the updates and restarting, the problem has not gone away - at least not entirely. I think dragging large layers around might be a bit smoother now, but changing a text colour or a "color overlay" colour still has a puzzling 0.5 second or so lag. I've been using Photoshop since ver 6, on various PCs and macs, and I've never noticed such a long delay for changing a colour.
The colour lag, while it shouldn't be there, is an annoyance I can live with. I'm very glad to be rid of that grey box, so thanks.