Weel the error is easy to explain, a trailing comma in the WHERE clause.
What this quesry got to do with the arcade, i don't know. Looks more like a UserCP query to me.
Can the user reproduce this, or was it a 1 time error.
Maybe he just clicked everywhere on the screen in teh heat of the game.
the person was last using the arcade, and then some how was unable to gain access to the site sayin: slight problem with database etc
the error keeps happening, just for the user , but not sure if this is any help, someone who also tried to access the site via google, showed up on the error log.
everythings been running fine till now
user cp? ive ran maintence and diagonostics, but problem still the same