I have a MacBook running OS X 10.5.8
Lately, with increasing frequency, it will freeze up. It happens as follows: I use it for a while, then close the lid, putting it in sleep mode. If I leave the lid closed only for a short time, it wakes up no trouble. However, after a while, it will make the JZZ-JZZ noise the CD-ROM drive makes when it is booting up. Once it makes this noise, if I open the lid, the screen stays completely blank, and the computer doesn't seem to respond to anything other than holding the power button down until it powers off. At that point, when I turn it back on it takes a really long time to boot up, but eventually does and acts normally. At least until the next time it freezes while in sleep mode.
So, what's going on, and how do I fix it?