Today we tried to upgrade our serial console server from the home-built rack mount machine running RedHat 6.1 that we put together something like 5 years ago to a reliable Dell 2450 we had around (old, but reliable) running RH Enterprise. This was "aborted", well, because it didn't really work out.
As it turns out, however, our Cyclades Y-series cards seemd to have an issue with running in the 2450. We have two different "style" cards, you see, and old-style full-height PCI card, and newer ones are a bit smaller. While they are supposed to be the same card, the "large" cards do not seem to work well in the presence of the "small" ones while in the 2450. Ended up going back to the old setup, and will see what Cyclades has to say about it.