Apple has released iTunes 10.4.1 for both windows and mac. iTunes 10.4.1 brought full screen support in Lion for the media software and usually this update fix many bugs. You can read the new change log of iTunes 10.4.1 after the jump.
iTunes 10.4.1 new changelog :
Fixes a problem where the media keys on some third-party keyboards work inconsistently with iTunes
Addresses issues with adding artwork to songs and videos
Resolves an issue which may cause iTunes to become unresponsive when purchasing an HD movie
Fixes a problem where iTunes may take longer than expected to open after waking your Mac from sleep