By all means, please don't use cjson -- it's buggy as hell -- but if you must...
I was bit by the same bug as described here: http://blog.extracheese.org/2007/07/when-json-isnt-json.html
So I produced a fix, here is the patch: http://www.vazor.com/media/python-cjson-1.0.5.diff
And the full package now called 1.0.6: http://www.vazor.com/media/python-cjson-1.0.6.tar.gz
And the changelog:
Changes in version 1.0.6
* Escape the solidus (forward slash '/') for encoding and unescape it for
* Correct read/write solidus unit tests
* Merge additional unittests from json-py for comments. All these tests
currently fail since comments aren't part of the standard json grammar.