This is definitely a user error, but the failure is silent which was confusing for a few minutes...
While developing a complex model.py, I introduced a bogus
casePCPid = models.CharacterField?('PCP',maxlength=20,blank=True)
instead of
casePCPid = models.CharField?('PCP',maxlength=20,blank=True)
Stupidity - all my own fault.
Unfortunately, 0 errors are reported when manage.py runserver checks the models, but none of the application tables showed up in the admin list. Took a while to track down and might be a trap for young players (like me)... I'll take a poke at it but this is probably a fix someone familiar with the model checking code will need to make. This is with the latest MR branch svn - I was using an older one but updated - same problem - models validate ok but the admin is missing ALL the tables.