I4GL out of temporary string storage

We are maintaining a number of SE 5.0 systems with applications written in 4GL. I have seen a number of reports generate a -4518 error "out of temporary string storage". There don't seem to be any tuneables here; a fellow worker suggested not passing too much data via "output to report", but what is "too much"? I have no idea what internals 4GL uses to send data using "output to report". The crude workaround is to create a global array and store the data there, then read from the array from the report with a for loop. This only works in our fortunate case where we know in advance the number of rooms in a hotel... Anyone have any ideas on how to troubleshoot this problem? TIA,