[HOpenGL] HOpenGL profiling problem

When I use profiling with HOpenGL, the file is empty (0 bytes) unless I change "mainLoop" for "return ()" in . Obviously, this program will terminate just after the window is created. Does anyone know the reason for this? (I'm using HOpenGL-1.01, GHC-5.02.1 under Windows98 + cygwin). -- Andre