It runs, runs not, runs, runs not, ...

Problem:  A REXX program works sometimes and sometimes not. 

 Hint:  If the program uses file I/O, check if you're closing all opened 
        files. The number of file handles is limited in an OS/2 session. 
        (see MaxFH on how to increase the number of file handles; see lsof 
        for getting a list of all open files) 

        Please note that the entry FILES=nn in the file CONFIG.SYS is only 
        valid for DOS sessions!