When I wake computer(iMac OS 10.5.8) from sleep it goes back to sleep\nagain almost immediately. I then have to wake it again and it stays\nawake. This behavior just started. I notice at first awakening that\nthere is activity on my external drive. The drive light then goes off\nand the computer goes back to sleep. The same thing happens with the\nexternal drive when I wake the computer the second time only it stays\nawake. Any thoughts?