Need help debugging a Singleton TypeError in my app.

marston-8Qo2DTIsO68RmelmmXo44Q@public.gmane.org
2006-12-02T20:47:39Z

I keep getting this error:

TypeError (singleton can''t be dumped):
    /lib/sql_session_store.rb:124:in `dump''
    /lib/sql_session_store.rb:124:in `marshalize''
    /lib/sql_session_store.rb:91:in `close''
    /usr/local/lib/ruby/1.8/cgi/session.rb:330:in `close''

/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/base.rb:1015:in
`close_session''

This only recently started happening and I haven''t changed much of
anywhere from before I started getting this error.

This happens when I''m updating a user account (I''m using
auth_generator).  Weird thing is if I take the image upload form field
out of the view, it runs fine... But I kind of need that form field to
update user icons (Again this worked fine a little while ago and I''ve
tried to revert any changes I''ve made since with no luck, obviously I
missed something.  I suppose I should write better tests :-\ ).  I''m
just having trouble finding out where the actual problem is.

What are the most common causes of the: "TypeError (singleton
can''t be
dumped)" error?  Thanks.