Use heavy plastic on earth instead of tar paper. Also close outside vents because they allow outside moisture to enter the crawlspace. You need a good dehumidifier for the extreme wet times. Keep the %RH below 60%RH. Get a good meter at Wal-Mart for $15. Check EPA's web site for a good dehumidifier.
http://yosemite.epa.gov/estar/consumers.nsf/attachments/dehumid_prod.xls/$File/dehumid_prod.xls?OpenElement