I deal with the same thing, on and off. SOmetimes it works good, other times, well, not so good. Changing the battery, bloodletting, facing Mecca, even sacrificing baby whales.... nothing seems to improve it once it goes downhill. Maybe these remotes just age rapidly. *shrugs*
I think my long term solution with be an all all new system. Go with a Viper again or something. Most systems nowadays have the lock remote system stock, so that'll do.