Output file causes trouble in findblack. Problem is solved. Argument with filename $2 wasn't quoted, confusing ghostscript.

 ./findblack '/media/XP_SYS/Documents and Settings/admin/Desktop/20090427.scans/haydn Jahreszeiten/haydn __jahreszeiten Edition Peters 7846 alternative version __Cfg.pdf' '/media/XP_SYS/Documents and Settings/admin/Desktop/20090427.scans/haydn Jahreszeiten/haydn __jahreszeiten Edition Peters 7846 alternative version __Cfg.test.pdf' 
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Processing sheet: /tmp/tempfile_findblack_10113-1.pgm -> /tmp/tempfile_findblack_10113.pbm
Error: /undefinedfilename in (and)
Operand stack:
 
Execution stack:
   %interp_exit   .runexec2   --nostringval--   --nostringval--   --nostringval--   2   %stopped_push   --nostringval--   --nostringval--   --nostringval--   false   1   %stopped_push
Dictionary stack:
   --dict:1150/1684(ro)(G)--   --dict:0/20(G)--   --dict:92/200(L)--
Current allocation mode is local
Last OS error: 2
GPL Ghostscript 8.61: Unrecoverable error, exit code 1