faulty back light on Hazro WA?

[Boozebeard]

Had my WA 3 months or so now and it's recently developed a small problem. The back light level keeps changing, it does it every 30 seconds or so and sometimes times flickers between a few different levels in quick succession. It seems to stop doing it or does it less often after it's been on for 15 minutes or so. Anyone else had/heard about this problem?

Also, what's the difference between the WA and the new WD?

Edit: I might be lying about the 15 minute thing.