I have been noticing some strange behavior.  Sometimes, receiving will try to PO-C a part on a PO...or Purchasing will try to enter a part onto an PO (not sure if I remember if there are problems with entering the part on an SO) and they will get an error that the part cannot be received or entered because there is no record in MTICMSTR.  I look, and sure enough the part is not in that file (even though I know it exists in the system).  I then do an IN-B, the part exists, but there is no entry in the used defined field.  I enter the correct user defined field and save the part and now the part is in MTICMSTR and can be received or ordered.
 
What is strange is that very few people here use IN-B and they all know that the user defined field should be filled in. (now people can of course make omissions, but I am wondering if this is an indication of something funny going on in the background (something getting deleted by DBA/EVO?))

in addition, i would reccommend running the Master Inventory Reconciliation SM-J-C. that will add record back to MTICMSTR IF the Item Record is already in the BKICMSTR.