Reported by Dunhamzzz | July 26th, 2011 @ 04:43 AM
There is a problem with the PRG::commonProcess() in that it does not encode the inputs it passes from $_GET to $params.
If an URL contains a % sign, it breaks apache(possibly others) and it throws a 400 bad request error. This problem arises when someone inputs a % sign and the PRG:commonProcess() turns this from ?foo=bar% to /foo:bar%
This has been tracked down to be an issue with the cores router not urlencoding the named params. I could not yet figure out how to fix it in the plugin if that's even possible.
Closing issue according to @burzum 's comment