Is "micronet.zip" the actual nodelist? Doesn't seem like it fits the zipped naming convention for standard nodelists. Maybe try renaming it to match the others, ie: micronet.z97, and see if it works. If it does, mystic may not be looking for and/or processing zip files that don't use the day numbering system.
Just something to try to narrow things down.
Regards,
Nick
... Inside every cynical person, there is a disappointed idealist.