Some people around the world are having issues with Lion when installed in mid 2010 macbook pro. -Constantly freezing -Freezes when in login screen Some people can do a turn around: disable the automatic swithc graphics in the preferences panel. Also, it seems to affect this card: NVIDIA GeForce GT 330M GPU PCIe (Bus) x16 (PCIe lane width) 512MB (VRAM) 0x0a29 (device ID) 0x00a2 (Revision ID) 3560 (ROM Revision) 1.9.21 (gMux Version) There are some people who are sending their laptops to Apple. In some ocasions Apple gives a new logic board, in others a new macbook, in others ocasions Apple just says 'nothing is wrong' (when definetely something IS wrong). You can find more information in this thread: https://discussions.apple.com/thread/3209415?start=0&tstart=0 Hope I can help some users posting this information.