Subversion integration error

Hi,

I'm using Subversion on a project. The connection to the repo goes fine, modified / new files are colored but I can't update / compare or commit anything, I get this error message :

Error:Fontconfig warning: ignoring C.UTF-8: not a valid language tag

It's working fine if I use svn command line or any third party svn manager (like RapidSVN).

Any ideas on what's happening ?

Thank you