I've the same problem with merged PDF-files from Plotmaker. ("A number is out of range" in Acrobat 7.0.x)
It's related to PDF bookmarks. Plotmaker / amynuni PDF converter fails (bug) to set the referenced page number in bookmarks.
Right click bookmark in Acrobat, select properties, .. no page number is given.
Håkon Alm
ArchiCAD 9 INT (2172) Win XP sp2
Acrobat Prof 7.0.5