Okay, you are right about fast ethernet having only 2 pairs in use. I read otherwise somewhere a while ago. Sorry for the misinformation!

About the continuity tester. I just used a 9 volt battery, and an LED to verify proper continuity. The battery was connected with clip leads and some small guage wire to two of the contacts on a patch cord plugged into a wall plate. Then an LED was touched againsted the corresponding RJ-45 contacts on the other end of the cable (the cable attached to the back side of the wall plate) where it was to plug into the switch. If it lit up, then I knew it was wired properly, or at least would work. I just repeated this until all of the wires were checked. This is how I found what I was doing wrong in my wiring of seven rooms in the house. Now even the longest run of about 200 feet (60 meters) works as well (same throughput) as a 1 meter crossover patch cord.