My 2009 mac pro has decided today to not go to sleep for no apparent reason. When I press the sleep button the screen goes blank but the fans are still working inside the mac pro and they dont go off like usual. its like it does the first stages of sleep but doesnt finish the job. The same state happens if you disconnect your iphone when the mac is asleep and it half wakes for a moment before going back to sleep (or at least it used to) I have tried SMC reset, NVRAM reset, quitting all apps, checking login items (theres only itunes helper), checking activity monitor for anything unusual, booting into safe mode, removing all usb cables, removing the network cable and turning bluetooth off. Whatever I do it wont sleep and Im at a bit of a loss as to what to try next. The only thing I installed today was wings 3d but I have deleted that with no change. If any information about my system is of use then here it is. The mac pro is a quad core 2009 with 12gb of ram, a sapphire mac edition 7950, crucial SSD boot drive, a hard drive for media and stuff that wont fit on the SSD and then one time machine hard drive. No hardware has been altered or changed for over a year and I did a complete wipe and reinstall of OSX about 4 months ago. USB keyboard and mouse, no airport card and the monitor is connected via a DVI cable. I wasn't sure if this should go in the mac pro or OSX section so feel free to move it mods.