|In order to solve this issue, first of all please ensure your version of Piczard is >= 220.127.116.11|
The problem is caused by HTTP compression.
(there is a known issue involving Flash player, Firefox and http compression)
In order to solve the problem you have to configure your system so that responses generated by Piczard HTTP handler "piczardWebResource.ashx" are not compressed.
|If you changed the URL of the HttpHandler that provides access to the Piczard web resources (in web.config -> Web Settings), then you have to disable HTTP compression for the new URL (not for "piczardWebResource.ashx").|