Rear hub cartridge bearing problem



My bike came with Ritchey Pro hubs. They have about 4,000 miles on
them, and I've been happy with them so far. But now I have a problem
with the rear hub.

When I tighten the quick-release skewer, the bearings "tighten up" and
the wheel doesn't spin as freely as it should. I beleive the problem
is that the spacers that serve as lock nuts on this hub (which has
sealed cartridge bearings) are each locked into place with a single
tiny hex bolt. On the drive side of the axle, the spacer appears to be
slipping when I tighten the skewer, and as a result the bearings get
squeezed. No matter how firmly I tighten the hex nut, and even if I
initially set the spacer so there's a tiny amount of side-play in the
bearings, everything ends up too tight when it's mounted on the bike.
It's a poor design, in my opinion.

Any suggestions on how I can solve this problem? Thanks.