Fixed an edge case where an Attribute Error could occur

TODO

@@ -17,3 +17,4 @@ bugs:
 * "ValueError: list.remove(x): x not in list" when trying to close a tab (error recurred after adding conversation support).  Tabs can be reordered, then closed, as a workaround.
 * Links must be right-clicked on to activate - can't left-click on the link directly.  This seems to be a pygtk issue
 * Sometimes tweets are posted when we display 'failed to post tweet'... need to differentiate between kinds of errors... or something.
+* Some posts by the user are still being counted as unread when they show up...

usercache.py

@@ -119,7 +119,7 @@ def add_to_name_cache(user, api=None):
         name = NameCache().map[user.screen_name]
 
     # Now let's look at the name we've got, and see if we need a better one
-    if not name:
+    if not name and api is not None:
         with api.lock:
             try:
                 new_user = api.GetUser(user.screen_name)