just ground yourself...it iwll save you "just incase". you can fry things on your board without you knowing, or them showing. say, for example, the parallel port. mine is fried on my NF2 board, and ESD is the only hting i can relate it to. it worked when i was using a parallel printer a long time ago, then i didnt use it, and i needed to plug in a scanner last month and theres no parallel port.
play it safe and ground yourself. even if you don't want to wear the strap...at leaset run a wire from baremetal on teh case to the side of an electrical box, a faucet, or the screw on the front of a plug or something. when you are working in your computer your wrists are usually resting on the edge of the case grounding you anyways.