Adding a Maven 2 POM from secure SVN on a non-standard port does not work

When adding a Maven 2 project to Continuum:

URL: http://machine.com:##/svn/project/trunk/pom.xml
User: user
Pass: pass

does not work. But if you enter:

http://user:pass@machine.com:##/svn/project/trunk/pom.xml

in the URL field, leaving the user and pass blank, it works. Credentials work when part of the URL, but not when put into the form fields on the page. Checking the log, it appears that the ":" is getting omitted when the final URL is synthesized from the 1st case above.