Unresponsive Script and Page Loading Very Slow

Hi Guys,

When I work on my easysocial configuration in the administrator backend it ALWAYS loads super slowly and I get a warning message - please see attachment.

I use firefox 35.0.1 (the latest version)
I also use firebug
... please don´t tell me this is an issue with firebug, all my other extension work fine with firebug.

This is driving me crazy! Any help there?

Thanks.