client.py and admin.py make the assumption (not made 
elsewhere) that hyperdb.Number() instances should be 
int()s.

cgi/client.py:

1328        elif isinstance(proptype, hyperdb.Number):
1329            value = int(value)
to
1329            value = float(value)


admin.py:

499          elif isinstance(proptype, hyperdb.Number):
500              props[key] = int(value)
to
500              props[key] = float(value)

and then we're happy.