Even though Items can no longer be seen in the Items window those that can be accessed from other windows can be used. Examples I've confirmed including applying an Earth Deity Hoe in Status of Items using the Prolong button and using Mercenary Orders to reinforce in Arena.
Only Items that cannot be accessed in some other window can not be used, if you have them.
For example, Relocation Orders, Green Wrap Books, Mania War Drums and Cosmo Hexagrams cannot be used if you can't see your items.

ShanToir edit at 2010-12-26 01:54:01