Routine just stops and doesn't indicate why

[goofykc]

I have a REXX routine that reads files of report output bundles. It reads a file, finds key words then starts writing an output file. Then finds key words again to close output file. Contines doing this until end of input file, then deletes the input file. Every now and then it will get a file that it doesn't get all of the way through and just stops. The routine has processed files taht were larger and smaller, there doesn't appear to be any invalid characters. Multiple runs will create identical (incomplete) outputs. Also if I put traces in the routine the file will stop at a different place and create a different size output. I put a trace in it and it executed and then performed a linein method instruction and just stopped. Any ideas what I can look at to see why REXX just stops? Also I moved the routine over to my desktop PC (from a Windows 2000 Advanced Server) and the routine ran all of the way through. My PC has version 2.1.2. The server has just interpreter version on it and I can't find how to make sure what exact version it is executing. All replies will be appreciated.%-)