OK, I think I have this figured out...
I am pretty sure that it would have just worked if you hadn't changed the job 2 minutes early. Here is the server log:
Code:
2008-10-06 02:22:00.124690500 bcron-sched: Reloading 'm3mary'
2008-10-06 02:24:00.126648500 bcron-sched: Warning: Ignoring unparseable line: '* 24 * * * zip -r /big/dom/xm3mary/m3mary/zip.zip /big/dom/xm3mary/m3mary/file.txt'
Note that at 02:22 you changed it from "24 *" to "* 24". "24 *" meant run it at 24 minutes past each hour. A time that didn't happen during the time it was set that way. "* 24" on the other hand would mean 24:00 which is not a valid time (midnight is 0:00).