I noticed that if I turn off suEXEC daemon mode, the APC cache seems to flush constantly. Only a few MB's gets cached, and then it is emptied. Also, the "Uptime" value in the apc.php script seems to stay at 0 and 1. If I turn on suEXEC daemon mode, the cache fills to a couple of hundred MB's and stays constant. What exactly does this Uptime parameter show?