I have a 2010 13" MBP with 8 GB RAM and a Corsair Performance Pro SSD. I downloaded and installed ML as soon as it became available (three days ago), and haven't experienced any problems until this morning. Now, Safari will start work fine for about 15 minutes, and then it will become unresponsive: I can switch tabs, but pages will not scroll and buttons will not work. Before the problem starts, Safari will consume apr. 1.5-2.5 GB of RAM, and feel very snappy. Then, it will skyrocket up to 5 GB and start paging out maybe 6 GB more. My Activity Monitor will show many the rest filled with Inactive Memory that the OS will not release until I quit Safari. CPU will shoot from about 15% to 99-120% I normally have 30-50 tabs open at any given time, and I know that's a lot. Never had this problem with Lion though, which is a shame since ML was so much better when it was actually working. If anyone can help me, I would appreciate it. Disk Utility, rebooting, resetting Safari, quitting Safari, and disabling the Adblock extension do not solve the problem.