[SVN] Commit error message

[Anthony Underwood]

Hi all,

I am trying to commit some snippets in the HTML mason bundle. However  
I get this error message. Any idea what this means, and what I need  
to do to get round it?

Thanks,

Anthony

Commit failed (details follow):PUT of '/svn/Bundles/!svn/wrk/ 
e01092b4-831b-0410-916f-925d6d15e231/trunk/Bundles/Mason.tmbundle/ 
Snippets/%3C%25doc%3E...%20(doc).plist': 412 Precondition Failed  
(http://macromates.com)