[SQLObject] help with circular foreign keys?

[inhahe <in...@gm...>]

sorry if there was something in the documentation i should have understood,
but i'm having this problem

the code:

class Pics(SQLObject):
  itemid = IntCol()
  picdata = BLOBCol()
  thumbnail = ForeignKey("Thumbs", cascade='null')
try:
  Pics.createTable()
  print "Created table Pics"
except dberrors.OperationalError: pass

class Thumbs(SQLObject):
  itemid = IntCol()
  pic = ForeignKey("Pics", cascade=True)
  picdata = BLOBCol()
try:
  Pics.createTable()
  print "Created table Pics"
except dberrors.OperationalError: pass

the error:

KeyError: 'No class Thumbs found in the registry [default] (these classes
exist:
 Log, Pics, RegisterSessions, SQLObject, Sessions, Users)'

that list is a list of all the tables created before i got to that point, so
i assume the error is that Thumbs must be registered before I can make a
foreign key to it, but then if I put Thumbs before Pics, Pics wouldn't be
registered yet when I try to make a foreign key to that.  how do i solve
this?  sorry if the answer is supposed to be obvious =p