A few quick words, as I don't use Fences 2 (Fences 1works just fine for me and does all I need it to do)
For the OP;
What graphics drivers? Have you tried others?
Have you been to the Toshiba site to see if it is a reported issue with HDMI use?
HDMI to a monitor, or a TV set?
Plugged in, or on battery?
To everyone else: I think the OP wants others to attempt to replicate the issue, rather than offer advice on troubleshooting, or in other words, DO try this at home.