problem with appending to a list, possibly mysqldb related

Here's the code:

class MyFrame(wx.Frame):

def __init__(self):
wx.Frame.__init__(self, None, wx.ID_ANY)
panel = wx.Panel(self)
dbconn = self.connect_db()
dbconn.execute("select namefirst, namelast from master")
bb_players = []

for x in dbconn.fetchall():
bb_players.append(' '.join(x))

cb = PromptingComboBox(panel, 'Choose A Player', choices=bb_players, style=wx.CB_SORT)

def connect_db(self):
connection = MySQLdb.connect('localhost', 'john', '*******',
'bbdatabank')
return connection.cursor()


The error seems to be in the for loop. I get this:

Traceback (most recent call last):
File "C:\Python24\myscripts\bbdata_access\bbdata.py", line 71, in -toplevel-
app = MyApp(False)
File "C:\Python24\Lib\site-packages\wx-2.6-msw-ansi\wx\_core.py", line 7700, in __init__
self._BootstrapApp()
File "C:\Python24\Lib\site-packages\wx-2.6-msw-ansi\wx\_core.py", line 7352, in _BootstrapApp
return _core_.PyApp__BootstrapApp(*args, **kwargs)
File "C:\Python24\myscripts\bbdata_access\bbdata.py", line 64, in OnInit
frame = MyFrame()
File "C:\Python24\myscripts\bbdata_access\bbdata.py", line 15, in __init__
name = ' '.join(x)
TypeError: sequence item 0: expected string, NoneType found
>>>

I know the method of joining the items in the tuple and appending to a list work, so I figure it has something to do with either mysqldb, or maybe the PromptingComboBox I am using.

Hope someone can spot the problem!

Thanks,
John
.