I am still running an older version 1.4.6 on one server, so maybe this has gotten fixed recently.  I had a one-week cooldown set on mining quarries.  The cooldown value was 604800.  Somehow this got interpreted as something closer to 3 months.  Either my server clock was WAY off one day, or the value overloaded somehow in the code.  Any ideas?  I supposed i can adjust those values but perhaps there was a real error.