Text displays incorrectly in Acrobat Reader after editing in pdfarchitect

Hi,

I am using pdfarchitect 2 (2.1.06.19758). I have a problem whereby I have edited existing text within a pdf document and added text. The document displays fine in pdfarchitect, but when opened in Acrobat Reader the edited characters and additional text display incorrectly, the characters overlap and become unreadable.

Images below are snapshots of the same document in pdfarchitect and Acrobat Reader.

Any help greatly appreciated.