One more question - compiling large code

I was just trying to compile a system containing macros that generate a large amount of code. I got this error: Compiled function can't be loaded: org.armedbear.lisp.demo_tmpHVF0FTR3_246 from org.armedbear.lisp.Pathname@2a31c2ec Does anyone know the likely reason for this? The code I'm compiling works with all other CL implementations I've tried. Is it just a matter of the code size? Thanks, Andrew