Looking for some help please.

[Irishwiseguy2006]

I have a cheapy but has been very great picture quality with no problems whatsover until a few weeks ago. I have a 42' Maxent Plasma. The problem is every once in awhile when the picture is really light colored in the bottom left corner maybe 6 inches i have this like "digital" looking flashing. Its so hard to explain what it looks like but it is really most notable when im in the PS store. its almost like a burn in because it looks like a half circle sort of but it flashes "sparkaly" like. Just curious if anyone knows what im talking about and if there are any ways to eliminate it. And Yes I DO do the multi color and all white maint. Thanks