An unfortunate byproduct of using the latest release candidate of bukkit is that it lacks optimization and 2 of our anti-lag plugins are not yet compatible with it. This is resulting in the server lagging a lot, as you all can easily see when opening chests, etc. The lag affects everything in the game, from how long the day/night lasts, how long iron takes to smelt, crops to grow, mobs to react to your presence and, unlucky for you, lava to flow and damage dealt to be updated.
Essentially, when you typed /home 1, you were already dead. The server just had not let you know yet.
A word of caution as we continue to experience this lag: try to avoid precarious situations in which you need to respond quickly to a threat, like mining under lava, or working on the edge of a cliff. The is unfortunately the price we pay for getting 1.3.1, for now.