Issues Merging A Branch On RIAForge

I was recently trying to merge the development branch of cfExcelProxy back into the trunk over at the RIAForge repository. Now I have to admit this was my first time doing this, so it might all be my fault, but for some reason I couldn't get the merge to work.

Using TortoiseSVN, I tried using merge and the "Reintegrate a branch" option. I then selected the branch as the "From URL" and tried a test. After a couple of seconds, I got this message: "Retrieval of mergeinfo unsupported by 'http://svn.riaforge.org/cfExcelProxy' ".

I then tried doing it command-line style, so I tried this in my local trunk folder:

This didn't work either. I kept getting this error message: "svn: Server sent unexpected return value (405 Method Not Allowed) in response to PROPFIND request for '/cfExcelProxy/branches/cfExcelProxy-rewrite'. What I'm wondering, though, is whether or not this is an issue with RIAForge or with something that I'm doing. I'm relatively new to the SVN world, so like I said I could be doing something wrong. I've already sent an e-mail through the contact form at RIAForge, but I suppose Ray's pretty busy with post-Gustav. Maybe one of my wonderful readers has an idea...