pc wont wake up again

Hello again,now ive got that other problem sorted, this is relatively minor
but its SO annoying, everytime the pc is left on for a while and goes into
hibernation or sleep after a certain time, when you come back up and try to
wake it up by moving mouse it wont budge, short press on power button does
nothing either, i have to force a shutdown and switch back on, it then says
resuming windows, but when it loads , my wireless mouse and keyboard never
work, so i have to force shutdown again and when it starts up from scratch
they are all going ok again, any ideas much appreciated , i am on windows
vista home premium, service pack 1, 32- bit operating system, 4GB RAM, intel
core 2 quad cpu
.