Any statement on that particular table seems to make it go to 100%. For example,

SELECT EVV_ORDER_NUMBER, EVV_CODE FROM EVV WHERE EVV_COMPLETED_DATE = '20090706'

I also notice ntdbsmgr.exe locks the actual data file after a query is run, is that normal?

My suspicion is the files are corrupt, but not sure if it would be the data files themselves or the DDFs.