Adobe Acrobat not printing full documents

We are having a printing issue with adobe acrobat 6.0. Upon converting a document from our AS/400 the docuemnt will print 4-5 pages correctly then the rest of the pages are all jargon. If we try to print the document a second time by selecting the print function within Adobe acrobat the document will print perfectly. Any reason as to why this might be occuring? Thanks