Editing PDF files, especially in such old versions of Acrobat, is always tricky and sometimes produces unexpected results.
For better results try using a newer version of the application, but ideally you shouldn't be editing a PDF file directly at all. You should go back to the original file format, edit it and generate a new PDF file from it.
I upgraded to Acrobat X and it makes no difference.
Try DC. But there's no guarantee it will work there, either. As I said, this is a tricky process and it often doesn't work as one expects it to, by the simple fact that PDF files were never meant to be edited in such a way.