hmm, interesting! I understand you but it's correct, try highlighting lines in your browser or copy/paste them into vim or any text editor. This problem was discussed before in Persian Computing mailing list. It's bidi display issue.

 "Since the Unicode bidi class of Eastern Arabic-Indic digits is EN, in contrast to AN, they are resolved in a different manner than Arabic-Indic ones while going through the Unicode bidi algo.", Shervin Afshar Said.

You can follow this here: https://groups.google.com/forum/?fromgroups=#!topic/persian-computing/602gqTIrlPQ