Rack::Lint::LintError with latest camping and rack

[Garret Buell]

I'm trying to use Camping from Magnus' repo (1.9.300) but running the
blog.rb example (or anything for that matter) gives me
Rack::Lint::LintError at /
Content-Length header was 0, but should be 548
Ruby 	C:/ruby-1.8.7/lib/ruby/gems/1.8/gems/rack-0.9.1/lib/rack/lint.rb:
in assert, line 16
Web 	GET localhost/

There are no errors on the camping output so I suspect something has
changed with Rack. What version of Rack do people have the examples
working with?

Thanks,
Garret Buell