Heritrix: Internet Archive Web Crawler

I created a job based on a previous job. I went to the
'URL' tab and clicked 'remove' next to the WWW
canonicalization rule. I then hit 'submit job'.

I was dropped directly back to the main 'crawl jobs'
page, with no further chance to edit the
job-config-in-progress. A red status line read
'Override changes saved'. There was no evidence the job
had been created.

The same thing happens if I 'remove' a filter then hit
'submit job'. It seems to be getting confused about
whether it's editting a new job or existing job.