Okay...before this goes any further, let's tone it down a notch here. It should be fairly self-evident that there is something wonky about how hostile mobs spawn on the server as a whole. Grimper and I were standing next to the Fenris grinder for a good 5-10 minutes earlier tonight, after we had gone down and checked out the setup down there, and not a single monster was drawn up into it; on any normal SP map, there would have been a constant stream of stuff getting killed there. TrashMan's certainly not imagining the hordes of Endermen that keep screwing up his stuff, and Grimper's spawner is twice the size of the Fenris one yet flat-out doesn't produce anything.
It's still up in the air what causes this behavior, whether it's just the 1.8 mob-spawning code versus the new 1.0 code, or something about the server setup/plugins, or some combination of the two. But I see absolutely nothing productive about saying something like, "Stop mentioning it, it's not going away." If it's a matter of needing the new spawning code, then that's easy enough. If the behavior remains the same after the upgrade is taken care of, then I think it's at least worth looking into whether it's something that can be resolved. It's not like the issue will go away if we plug our ears and pretend it's not there.
(And it went further before I could even get this written. Fantastic.)