I returned to my computer today to notice I had the following error:
(145, "Table './databasename/comments_freecomment' is marked as crashed and should be repaired")
Well, crap. The solution is quite easy, however:
mysqlcheck -uUsername -pPassword databasename comments_freecomment
Now you know what you already know, you can fix it:
mysqlcheck -r -uUsername -pPassword databasename comments_freecomment
If that doesn't work, you can try a slightly different method. First, go to the location where your databases are stored on the disk (most likely something like /var/lib/mysql/databasename). Next, stop the database -- and try to free up as much memory as possible. Then run:
myisamchk -r comments_freecomment
If that doesn't work, try to force it:
myisamchk -r comments_freecomment -f
Hope that helps!