Why checking out working copy with svn:// access method, with 127.0.0.1 fails , but,with localhost works?

Question

Hi!, I have setup svnserve server (1.6.5,plain, without apache) on Fedora. I start the svnserve with the command 'svnserve -d --foreground --listen-port=3690 -r /usr/local/svn-repos/proj-test'

When user trying to checkout working copy from the local machine with command

'svn checkout svn://127.0.0.1/proj-test' gets following error

svn: URL 'svn://127.0.0.1/proj-test' doesn't exists

but, 'svn checkout svn://localhost/proj-test' works.

I am curious to know why using 127.0.0.1 with svn:// fails?

Thanks. Banani