[Lynne]

If you run repair/optimize on your threadviews table and get told:
threadviews Check Error: Incorrect file format 'threadviews'

Then run these queries to drop/recreate the table:

1:
DROP TABLE IF EXISTS threadviews;

2:
CREATE TABLE threadviews (
threadid INT UNSIGNED NOT NULL DEFAULT '0',
KEY threadid (threadid)
);

If you have a table prefix, then be sure to add that (ie. prefixthreadviews)