Motherboards Mobo screw fiber washers - Fairly possibly a stupid question!

Um, right so i'm moving my mobo to a untried case. I've managed to lose ane of the red washers that sit out under the head of the screws holding the mobo in. Can I do without Or should I get another? all the process into town for a small red washer...

Source: http://forums.bit-tech.net/showthread.php?t=224173&goto=newpost