I noticed i wasn't doing nothing and my cpu was at load temperatures, when it should be idling. Using "top" i noticed famd was using all the cpu time, till i rebooted the machine. Killing Xorg didn't solve it, only made kde take like half an hour to fully load. It has happenned to me like 3 times one month ago in a week. Now it happened again, before i tought it was something related to kde, beacuse i was using unstable 3.5.1 Now i saw what it was. It's a confirmed bug, because i installed gentoo to a friend of mine, and i talked to him today and he confirmed me he was having the same problem. I'm using gentoo-sources-2.6.14-r5, he's using gentoo-sources-2.6.15-something.
Use gamin instead; fam sucks.
see previous comment. fam is unsupported upstream and only around for historical reasons, gamin is first choice.