I've tried to look for it on other brands, but I haven't seen it. Attached is a zipped 1280x768 test jpeg. Bring up this jpeg on your plasma and see if the white is consistent everywhere on your screen or if the colored bands affect the white in adjacent areas. The effect is that the plasma looks very similar to the ghosting on passive matrix lcd screens.
Pioneer engineering is aware of the problem, but they told me they do not intend to address it on current or future models. So who knows. It is not all that annoying unless you are watching for it. Howard
ps- resize the jpeg to 848x480, 1024x768, 1366x768 etc depending on your plasma's native res...
piotest.zip 3.919921875k . file