Pat Shaughnessy's Paperclit problem

I'm using Pat Shaughnessy's paperclip
cause I need to store pictures in database. When I set :storage
=> :database in the avatar I get an error when starting server:

`[]': Symbol as array index (TypeError)

Had anyone this problem before?

My system:
Ruby 1.8.7
Rails 2.3.5
Hobo 1.0.0
Paperclip 2.2.6 (Pat Shaughnessy's)
Win XP