I have a simlar problem to Resea below, but need some exrta help as I really can't find how to fix it.
I'm using v 184.108.40.206 and the follwing error appears on my store's home page and in my admin panel when I click on "who's online":
1034 Incorrect key file for table 'cbwhos_online'; try to repair it
[delete from cbwhos_online where time_last_click < '1172823302']
I've tried to find the file in phpMyAdmin, but can't. I've been going round in circles for ages and can't figure it out....
I'm not too clued up, so please don't use long words...