TSImport: Slips are going to wrong case name

SUGGESTED

Our firm's file naming convention is set up as XXX.NNN (i.e. BEL.100).  On some occasions, I have had to re-create files so I name would rename the "bad" file as BEL.100CLOSED and then re-create a new file named BEL.100.  I would then re-classify the one named BEL.100CLOSED as a "closed" file. 

My problem is that when I import slips from a .txt file, the slips are going into the closed file (BEL.100CLOSED) rather than the new, open one.  I have tried to change the name to CLOSED.BEL.100 but it still goes into the wrong file. 

Does anyone know why this would be happening and what I can do to prevent it?