Harddisk behaves weirdly after hibernation

I just noticed something quite unusual on my laptop (Dell Inspiron 1721). After hibernating, and waking up again, the harddisk enters "sleep mode" very often. In other words, it spins down after a much shorter period of time. Once it is needed, I can hear it spinning back which takes about a second (possibly a little less). Even though this is not a serious problem, this causes software to be unresponsive for that second while the harddisk comes back. Is there any setting which I could measure before and after hibernation in order to diagnose this better?