Crash on entry editing

In the Account view, I got this crash while tabbing from the date field to the payee field:

Application Identifier: com.hardcoded-software.moneyguru
Application Version: 2.5.5
Mac OS X Version: 10.8.2

Traceback (most recent call last):
  File "/Users/hsoft/src/moneyguru/build/moneyGuru.app/Contents/Resources/mg_cocoa.py", line 1426, in setText_
    self.model.text = value
  File "/Users/hsoft/src/moneyguru/build/moneyGuru.app/Contents/Resources/py/core/gui/completable_edit.py", line 122, in text
    if self.candidates:
  File "/Users/hsoft/src/moneyguru/build/moneyGuru.app/Contents/Resources/py/core/gui/completable_edit.py", line 112, in candidates
    self._refresh_candidates()
  File "/Users/hsoft/src/moneyguru/build/moneyGuru.app/Contents/Resources/py/core/gui/completable_edit.py", line 45, in _refresh_candidates
    self._candidates = dedupe([name for name in self._candidates if name.strip()])
  File "/Users/hsoft/src/moneyguru/build/moneyGuru.app/Contents/Resources/py/core/gui/completable_edit.py", line 45, in <listcomp>
    self._candidates = dedupe([name for name in self._candidates if name.strip()])
AttributeError: 'NoneType' object has no attribute 'strip'

It's a bit hard to reproduce. It happened to me twice and it seems to be related to split editing and/or MCT balancing. That crash happened right after I did a MCT balancing (which creates a split). And then, I created a new transaction and tabbed from the date field into the payee field. This is when the crash happened (both times).

Now I can't seem to be able to reproduce it...