RSpec: adding "--format s" to spec.opts causes rake spec to fail

Windows XP SP 2
ruby 1.8.5

gems:
rails 1.2.3
rake 0.7.3

plugins:
rspec 1.0.8
rspec_rails 1.0.8

Running spec with "rake spec SPEC_OPTS="--format s" and "ruby script/
spec --format s" works fine.

But if I add "--format s" to my spec.opts then rake spec fails (see
error below)

here is my spec.opts:
--colour
--format s
progress
--loadby
mtime
--reverse
--drb

Error:

D:\dev\project>rake spec
(in D:/dev/project)
(druby://localhost:8989) ./script/../vendor/plugins/rspec/lib/spec/
runner/behavi
our_runner.rb:98:in `find_paths': File or directory not found:
progress (Runtime
Error)

Figured it out...removing the option "progress" fixed the error