Hi, I'm running PS 5.1 64bit for mac (not extended) and I've experienced 2 problems in the last day. 1) after working on an image (psd in 8 bit grayscale) for a little while my ability to switch between tools became impossible and I couldn't change screens (the change you get by pressing the "f" key). I tried restarting the program to correct the problem, but it didn't work, so I had to reboot my mac to solve the problem. 2) also after working on an image (same psd) for about the same amount of time (45 minutes) the info panel that gives the K and the CMYK stopped continuous operation (it would only show data if the cursor was moving). Again I had to reboot my mac to remedy the problem. I did a disk permissions repair just in case as well as a ram and hard drive check, and they all turned out to be normal. I know this will sound rude, but hopefully someone will find this helpful in remedying this version (5.1) as opposed to ignoring because 6 has come out.