WGT is running off of Adobe Flash. Flash is not meant to run resource-intensive programs/games. WGT is [fairly, but relatively weakly] resource-intensive.
That's why, ocassionally, you'll see the meter stutter and skip a few inches off the screen. It's not your computers problem... Your computer has no trouble at all running Flash, it's Flash's problem. Flash was designed to run programs and games at a very low fps, and it does so. The harder it is to run a game, the more problems that will arise with Flash (WGT uses high quality screenshots, runs at a huge resolution, many processes taking place, etc.).
If you capture video footage of the meter and slow it down, you'll see that the meter skips a few pixels instead of covering each one. This further proves my point that this is Flash's problem, not yours or WGTs.
Until WGT is running off of Microsoft Silverlight, you'll see no issues resolved. This isn't WGTs fault. They programmed the meter flawlessly.
Also, this is thread #85,031 having to do with the meter. Quit your bitchin'.