Finally fixed this problem. The only way that I was able to fix it was to uninstall TortoiseSVN-1.4.3, install Subversion 1.4.3, then reinstall TortoiseSVN-1.4.3.
I think the problem was not having Subversion 1.4.3 installed and using a newer cygwin client, but not really sure :-) Anyway, fixed now. -- Laura Stewart
