Hi RyGa160,

 

Does it happens with special file? special size? I can not reproduce this issue on the demo page with firefox 10.0.2. More information will very helpful to find out the problem.

 

By the way, please check your session setting, ensure that the session function has not be disabled. 

 

Please refer to http://cutesoft.net/forums/thread/67699.aspx, it should help.

 

Regards,

 

Ken