I've searched the forum on this topic, and have found some references to the problem I'm having. I am running SW 2011 sp4
  I have a couple of drawings made in an older version of SW, not sure 2008 or 2009?.  The drawings have been saved with the views set to draft quality.  The problem is they do not pdf properly, and all my attempts to convert them have failed.  I have clicked on the edge of the views, and selected high quality.  The selection seems to stick, and then the dialogue disappears (for good).  The view is still draft.  I have set the "convert draft to high quality' at print, and it fails to convert one or more views.  This is to do with the drawing view being set to draft, it is not an image quality thing.  Any ideas?

Certainly does sound like a bug to me.  Step 1 would be to contact your VAR support team to see if they have seen this before.  I've found they can sometimes guide me through some pretty tricky stuff that would not be obvious to the average SolidWorks or Windows guru.  Failing that, try either repairing your SolidWorks installation or restoring your windows configuration from an earlier restore point.  Hope that helps.

Problem solved.  Our VAR (Hawkridge Systems), put me onto the solution.  One of the sheet metal parts in my assembly was showing a general fault in Tools -> Check.  This "fault" does not cause any problems in the model, it just seems to force the assembly drawing into draft quality views.  Anyways, turning off the system setting under Performance -> "Ignore self-intersection check for some sheet metal features" cleared up the problem, and I'm a happy camper.