u guys probably have torn meniscus', apparently its getting pretty common, as i had one and had to have it surgically repaired...pete sell just tore his awhile back, it sux...i would only feel it whne i was rolling, and someone put pressure on my knee from my butterfly guard.. or pushed it or crunched it into my body..my knee would "lock" so to speak..and then id have to kick it out...sucked hairy monkey balls..but the meniscus thing is pretty common, and insurance covered the surgery...other then surgery, u can take an anti inflammatory which is supposed to help but didnt on me, cuz i guess my was torn beyond repair...hope this helps