Problem linking a lablgtk2 program under MinGW

This is the command which fails:

ocamlopt.opt \
  -I +lablgtk2 -I ../libvirt  unix.cmxa lablgtk.cmxa \
  ../libvirt/mllibvirt.cmxa gtkInit.cmx -o mlvirtmanager.opt mlvirtmanager_helpers.cmx mlvirtmanager_connections.cmx mlvirtmanager_domain_ops.cmx mlvirtmanager_mainwindow.cmx mlvirtmanager.cmx
gcc: @C:/Users/rjones/AppData/Local/Temp/2\camlresp7bf875: Invalid argument
Error during linking

MinGW's gcc doesn't understand the @syntax for specifying an extended
command line.  Although this only happens under lablgtk for me, I'm
not so sure if it isn't a general OCaml problem.  In any case does
anyone know how to solve it?

Rich.

-- 
Richard Jones
Red Hat