iSafe is a plugin that has frequently updates. iSafe can have several updated a week, and sometimes only one. Once a new version of bukkit is released (a recommended/beta build) iSafe will update as fast as possible. If Minecraft is updating to a version that's incompatible with the current bukkit, then iSafe will try to find a compatible build for that Minecraft version. (I only recommend using a recommended/beta build of bukkit)

And you do not need to bother visiting iSafe' pages to check if a new update is available, iSafe does that for you! iSafe automatically checks if there's an update available at BukkitDev and if there is so, it sends a notify to the console and the Administrators on the server.

The update checker will check for updates approximately every 30 minutes. It will not download anything; only attentive you aimed at the new update. The update checker will also warn the users with the permission iSafe.admin or if the user is OP, on join.