Subclipse does not use the Eclipse proxy information, which causes errors like the following when trying to connect to a SVN repository -
To use Subclipse behind a proxy server, perform the following steps -
1. Open file C:\Documents and Settings\MyUserId\Application Data\Subversion\servers in your favorite text editor.
2. Near the bottom of that file is a [global] section with http-proxy-host and http-proxy-port settings.
3. Uncomment those two lines, modify them for your corporate proxy server
4. Go back to the SVN Repository view in Eclipse and refresh the repository!