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