Ok, I dropped the big money for the Cadillac of boat trailers for my new sunfish, a Trailex SUT-200-S. The trailer was shipped via UPS without a problem, assembled per instructions, all fasteners torqued per specs, tire pressure set at 15 psi. I just made my first test run, empty trailer, no boat. From about 30 mph on up, the trailer shakes, vibrates, and even jumps off the ground (without hitting any bumps - smooth road). The vibration was so severe at times, it even blurred the mirrors on my little truck. At times it would settle down, then the vibration kicks back in, almost like some sort of harmonic vibration running up and down the whole trailer. Total test run, maybe 5 miles. At this point, I'm afraid to even attempt to tow my boat on this trailer. I understand the trailer is designed to flex, to help absorb road shock, but does this trailer dampen road shock, or does the boat absorb the trailers vibration? It's Saturday so I can't contact Trailex until next week. Has anyone else experienced this problem?