We have recently found a bug in the game with the item inventory.  Some users were able to keep more than 100 screws in a single “etc.” inventory slot. The maximum number of screws allowed per slot is 100.
 

All users with this bug will have until July 18^th to make necessary adjustments to keep the screws at no more than 100 per slot. After the 18th, any slot with over 100 screws will be deducted to the 100 screw maximum allowance per slot. Any screws lost as a result will be later compensated through mesos (50 per screw, store price).
 

We sincerely apologize for this inconvenience.
 

-The MapleStory Staff-