To repair the table in question issue the command
myisamchk --recover /var/lib/mysql/DATABASENAME/TABLE_NAME.myi
(Where DATABASENAME is the name of the database you are working with and TABLE_NAME is the name of the table to be checked.)
If this does not fully recover the table, you can re-run the command replacing –recover with –safe-recover which is slower and more thorough.
They only take a dump like that if there was some serious conflict during a row level lock, or bad write (bad sector).