i believe the problem is here --
the maximum prefix length is 255 (or 1000 bytes for MyISAM and InnoDB tables as of MySQL 4.1.2), and you have article's prefix as 65K
`other` TEXT( 255) NOT NULL ,
`article` BLOB( 65535) NOT NULL ,
INDEX ( `other` , `article` )
if you think about it for a second, 100 oughta be plenty
a regular INDEX, as opposed to a FULLTEXT index, is used to find a particular row, based on matching data values from left to right
to have an index on (other,article) would be useful only if you had a WHERE clause like this --
WHERE other = 'a specific value which exactly equals the value in the column for exactly 100 bytes'
AND article = 'another string which ... well, you get my point, yeah?'