non-repeatable "undefined error 'path'" error

I'm seeing an error the first time I run a create after restarting my
webserver (thin). Same create succeeds on all following attempts.

Details:

ruby 1.9.2dev
rails 2.3.2
rack 0.9.1
thin 1.0.0
rmagick 2.9.1

I'm trying to get attachment_fu working in my current setup and have
run into a rather strange situation. The first image I try to load
produces the following diag in the logfile:

I think it's a bit too early to run all that stuff on 1.9.2.

Dmitry

certainly a valid reply, not exactly what I was expecting though...