Question : Problem: Motherboard Grounding to case

Correct me if I'm wrong, but a motherboard is supposed to ground to the case.  If the case is sitting on a metal rack and the metal rack is sitting on carpet, couldn't the case pickup static from the carpet through the metal rack? The case sits directly on the metal rack...no rubber shoes.

Answer : Problem: Motherboard Grounding to case

The proper technique involves lining up the holes in the motherboard with the proper placement of the case standoffs.
The washers can be used or not as the motherboard will still be grounded through the screws or the standoffs. The important thing to remember is not to have standoffs where there are no mounting holes on the motherboard.
standoffs touching the motherboard where no mounting hole is present will short out the motherboard.
Some cases will have built n  raised mounting points rather than tapped standoff holes  that will not line up to a motherboard mounting hole. In this case you need to cover the raised mounting hole with electrical tape or some other non conducting material.
Here is a guide for mounting motherboards that may help.
http://biorobots.cwru.edu/server/howto/buildcomp/mountmobo/