.idx files not being created

I could really use some help - this is really stumping us.  We have a cloned program of IC522 that we named BI523.  It's been working fine on our AIX operating system..  This weekend we moved our Lawson applications from AIX to Linux.  Now when we run the job - the custom program is no longer creating the .idx file and we can't figure out why.  I also ran the Lawson-delivered IC522 program and it does create the .idx file either.  All we did was bring the code over from AIX to Linux and recompile all the programs - no changes were made.  We have had multiple challenges with Lawson running on Linux - this is just yet another one.  It's starting to become a big problem because we can't get our item data interfaced into our Surginet system.