Description of problem:
When I add a new entry to revelation, it crashes with the following trace:

Traceback (most recent call last):
  File "/usr/bin/revelation", line 266, in <lambda>
    self.tree.selection.connect("changed", lambda w:
self.__state_entry(self.tree.get_selected()))
  File "/usr/bin/revelation", line 305, in __state_entry
    e = self.entrystore.get_entry(iter)
  File "/usr/lib/python2.4/site-packages/revelation/data.py", line 400, in get_entry
    e = self.get_value(iter, COLUMN_ENTRY)
  File "/usr/lib/python2.4/warnings.py", line 61, in warn
    warn_explicit(message, category, filename, lineno, module, registry)
  File "/usr/lib/python2.4/warnings.py", line 82, in warn_explicit
    for item in filters:
TypeError: unknown type (null)


Version-Release number of selected component (if applicable):
0.4.7-5

How reproducible:
Always

Steps to Reproduce:
1. Click "new"
2. Enter a name for the entry and a pw (I rarely use other fields)
3. Click "Update"
  
Actual results:
"Unknown Error" window pops up. If you click Continue you can see the the entry
is saved. In fact, everything works ok except that every time that entry is
clicked, including on subsequent runs of Revelation, the error above still pops
up. Afterward you can view the entry. I assume this is Revelation not dealing
well with blank fields. 


Expected results:
Same, but without the "crash". =;)

Additional info: