4gl debugger - "USE" command limits?

Morning! HP-UX 11i, IDS 9.30HC5, 4GL 7.20 UD8. Yup. Old versions. Sorry 'bout that, reasons discussed ad nauseam previously. However, does anyone have any information on limitations in the 4gl debugger, specifically we're getting a problem with the "USE" command to show the source code under a debug session. We have a program we can't debug properly because when we issue "USE" to one particular library path, the debugger coredumps and quits. The library consists of 45 4gl files, with 48000 lines of code containing 323 functions, 304 cursor declarations. If there's any more stats you need, I can find them out too. I can't find anything in any manuals - online or our old paper ones - about limits although I recall something (which i can't find now, of course!) about functions with more than - I think - 2k lines of code? Thaks guys Malc