sleep problem and macbook pro

Users have been suffering from what is apparently not a hardware problem. When putting their computer to sleep, they unexpectedly hit a snag in the reliable and wellcharted rivers of Mac Os X, the display on the macbook pro would not light on. It refused to wake up and stayed dark.
Yes, it is bothersome. The fans are humming and there is no way you can end this form of hibernation but to force stop the macbook pro. Each and every time your macbook pro sleeps for more than 15 minutes. After trying several routines, advertised by Apple and the supportpeople, advise from the dealer, installing firmware, updating software and looking over the possible terminal commands (f.e. how to stop hibernating or safe sleep mode) I gave the macbook pro to the repair shop. Nothing changed. Finally, after rigorous testing and trying, I found two solutions to the sleep problem that mac lap tops have suffering. After installing the freeware iLid ( a preference pane) and Wake Assist the problem has vanished.