Trouble with Content Security Policy (CSP)
In the latest Firefox 33 there seem to be an issue with Content Security Policy (CSP) and how it handles url that are url encoded. For instance when some CSP directive is set to like https://mywebsite.com/application/do;jsessiond=1234 - it will get URL encoded so the ; gets replaced by %3B. In Firefox 32 and earlier this worked, but not in this new solution.
Opaite Mbohovái (1)
It may be that it needs a header application/x-www-form-urlencoded is this included in your url request as well as charset UTF-8?
If you select a different encoding via web dev https://developer.mozilla.org/en-US/d.../encodeURI
This sounds like what it did before? http://www.justarrangingbits.org/fire.../index.html