Software for sandbox mode wanted
 

Sandboxie since quite some time now has given me increasing headaches. Once having worked reliable, since months now I face stuttering videos, crashing flash player and crashing Firefoxes. With recent update of FF to 34.0.5. I cannot even get FF running in the sandbox, even when reinstalling Sandboxie (4.14). Tried multiple things, and was in their forum, without any curing results.

I want some alternative to Sandboxie, to have webbrowser and email client working inside the sandbox.

Does anyone know alternative software to Sandboxie? Free or cheap price, but nothing for 100 bucks or so. Money is a factor.