Best Subversion clients for Windows Vista (64bit)

I have been using the 64Bit version of TortoiseSVN for ages and I have never had issues with it on Windows 64Bit or Vista 64Bit. I am currently not aware of any other similiar SVN clients that do work on Vista. Is it possible the problem could lie within the configuration of TortoiseSVN or even the installation of Vista? Is the problem occurring on Vista native or SP 1?

TortoiseSVN in combination with VisualSVN for Visual Studio.

I'll second Diago's answer. I use TortoiseSVN on Vista x64 pretty heavily.

I did upgrade directly from an older version to 1.5.2 though, and never used 1.5.1. Have you tried 1.5.2?