TracHoursByComment breaks GridModify plugin

[chris@…]

I just installed TracHours on my Trac that already had the GridModify plugin installed and working. After enabling all of the TracHours plugins, the GridModify plugin stopped working, ie: after editing a field in the grid, it would not save.

I turned on logging and found the following error:

Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/GridModify-0.1.6dev_r12235-py2.6.egg/gridmod/web_ui.py", line 105, in process_request
    ticket.save_changes(req.authname, None, now)
  File "/usr/lib/python2.6/dist-packages/trac/ticket/model.py", line 360, in save_changes
    listener.ticket_changed(self, comment, author, old_values)
  File "/usr/local/lib/python2.6/dist-packages/TracHoursPlugin-0.6.0dev_r12205-py2.6.egg/trachours/ticket.py", line 111, in ticket_changed
    self.add_hours_by_comment(comment, ticket.id, author)
  File "/usr/local/lib/python2.6/dist-packages/TracHoursPlugin-0.6.0dev_r12205-py2.6.egg/trachours/ticket.py", line 129, in add_hours_by_comment
    for match in re.finditer(self.hours_regex, comment):
  File "/usr/lib/python2.6/re.py", line 186, in finditer
    return _compile(pattern, flags).finditer(string)
TypeError: expected string or buffer

So I turned off the TracHoursByComment plugin, as that looked like it was expecting a comment or atleast as empty string, and GridModify works OK now.

I won't be using TracHoursByComment anyway, but thought you might like to know.