These came from an article written by Torry Stiles, aka Torry...

LOGJAM-What occurs when the cache owner fails to replace the cache log.
McBEEF-Complaint about the placement of Happy meal toys in caches.
ZIPBLOCK-The bad spot in a cheap baggie that keeps it from sealing properly.
BUGHO-Someone who revisits caches just to snag the travel bugs.
CACHE RELIEF-A handy tree away from the cache and fellow cachers.