sudden NameError after things were working

Hi,

I am using BackgrounDRb, and have one worker class, parser_worker.rb.
I generated this, added code to the do_work method, and was creating
the workers succesfully from within my rails app. Then I changed a
bit of code in the function that creates the worker, and in the
worker's do_work method. I restarted BackgrounDRb and then restarted
WEBrick. Now when I hit the line of code that creates the worker
(which wasn't changed at all) I receive the following error:

NameError (uninitialized constant ParserWorker):
     (drbunix:///tmp/backgroundrbunix_localhost_2000) /usrlib/ruby/
gems/1.8/activesupport-1.3.1/lib/active_support/dependencies.rb:100:in
'const_missing'

All I did was change some code within a functioning framework. Does
anybody have an idea of what the issue may be?

Thanks,

Simon