Print nonsense error message instead of crashing in windows viewer.
Print nonsense error message instead of crashing in windows viewer.

darcs-hash:20090819005156-f546f-5f3c0de4a5d0fa9794e425f48d33ddb3d3b79199.gz

nqv/mupdf,nqv/mupdf,nqv/mupdf,nqv/mupdf,nqv/mupdf,nqv/mupdf