I also know someone who has the problem down the left hand side.
As mentioned, turn screen off and on again temporarily fixes the issue, so I wonder if this is a software or hardware bug?
If it was software, you'd expect many more people to have it. Maybe it is a hardware/firmware bug and turning screen off/on reinitialises something.....
Yes, mine is the same, and it also resets with the off/on switch. Mind you when you change from Landscape to Portrait, the 'dead area' becomes live again. It's also not the full length of the side in Landscape as a small portion at the top remains active.
I don't think it's hardware, but something in the software.? Anyway, it doesn't really bother me as I only use the Hudl infrequently.