I have a 2.13ghz MBA with 2gig of ram.. I upgraded to Lion and now the CPU is always running high.. it's at 100% when I watch a Youtube video on Chrome.. it's become totally unusable.. Has anyone else had this problem? Is there anyway for me to downgrade the OS? I installed Lion on my core 2 iMac, and now that's just a dead stick.. freezes every 10 minutes... I've done all the software updates, cleaned up my HD, fixed permissions.. I'm up to my wits end!