Problem: PDF files exported from ArcMap will not print using Adobe Acrobat 4.0
ArcMap generated PDF files containing annotations or labels will not print using Adobe Acrobat or Acrobat Reader 4.0.
This is an incompatibility with Acrobat and Acrobat Reader version 4.0.
Solution or Workaround
Upgrade to version 4.05 or higher, which is available free of charge from Adobe.