MacBook switches to hibernation during sleep

Hi there,

Since installing the MacBook Pro/Air 2.0 update, while my computer goes into sleep mode, after a certain amount of time it switches to Hibernation mode automatically.

This means that after X amount of hours (could not figure out yet how many exactly), when I wake up the computer, it actually will wake up from an hibernation state, much more slowly.

Anyway to restore the old behavior of waking up from sleep only, regardless of how much time has passed?

Thanks!