Bitcoind becomes non-responsive over JSON-RPC, have to manually restart all the time
Upgrade to the very latest stable version. We saw alot less memory leakage with .10 on ubuntu
run a cron job to restart it every night around 4:00 am est when there are fewest ransactions. This will cut down on memory leakage
make sure your box has at least 4 gigs of ram and a 2 gig swap partition.
give us some more info here. like linux distro, machine stats and what kind of rpc calls u often do.