Can't check out working copy

OK, I've installed the requirements and followed the instructions for
bootstraping from a Tarball per the install docs. But when I go to
check out a real Subversion working copy I get the following error:
 
$ ./svn checkout http://svn.collab.net/repos/svn/trunk svn
subversion/libsvn_ra/ra_loader.c:209: (apr_err=170000)
svn: Unrecognized URL scheme 'http://svn.collab.net/repos/svn/trunk'
 
What is causing this error?

Info on my system:
Red Hat AS v2.1
Subversion 1.0.3
Neon 0.24.5
Berkeley DB 4.2.52
Apache 2.0.49
 
Thanks for the help,
 
Ed Murphy
The University of Arizona
Received on Wed May 26 01:09:11 2004