What can be wrong with PDF/computer. In the attached picture there are fragments from one PDF which in adobe reader (10.1.3) shows boxes instead of characters. Opening same pdf with different program, I get correct result.
Extended font pack didn't solve the problem. Odd thing is that some characters in the middle of the string are missing and same character A is shown in the beginning, but not in the middle. When looking to document properties, it shows as used fonts as in attached picture.