A few people are getting PAL DVD discs instead of NTSC discs. For them it doesn't matter if the Project is SD or HD. Nor does it matter if they are using Bogart 5.5c, or Bogart 6.1. Germany is looking into it. A couple have been able to delete Arabesk 6.3e in the Install Product menu, then install Arabesk 6.0a from the May Add-on Disc, and the PAL problem is gone. One guy had to do a destructive full install of Bogart 5.5c, and then install Arabesk 6.0a.
Arabesk will burn either PAL or NTSC discs, depending on what format the Project is set to. So make sure you select NTSC. In Bogart 6.1 the default is PAL, so maybe some aren't changing it to NTSC before starting a new project?  I started this topic in the Forum for this possible bug: 

http://www.casablancaforum.us/viewtopic.php?f=29&t=6897