Those are not plasma, but TFT and LCD.
The 226 is a 1680×1050 monitor. Is your graphics card set to that resolution? It needs to feed the 226 monitor its native resolution, or else you’ll be seeing softness and other scaling issues.
Another thing: does the same happen with other fonts?
If you export a still file at the native resolution you are working on, are you seeing the same issue on that exported still? Can you export a still and post it, so we can get a better idea of what it looks like?