I've recently been getting the following error trying to re-check out cadkit with SVN on windows
svn: REPORT request failed on '/svnroot/cadkit/!svn/vcc/default'
svn: Can't find a temporary directory: Error string not specified yet
I can reproduce this on two machines, using different svn clients, and I have no problems with other repositories.
It might be worth seeing if you can reproduce this problem on a fresh checkout.
Pete