little grey boxes...

[typhoon]

Hi, I am new to this forum, tried the search thing but...
Anyway, what are those anoying grey little boxes that flash at times when you are watching HDTV.  They appear on all channels that I watch.  Some chaneels are worse than others.  No channel is perfect.  Is this the result of a not so great signal on my part or maybe a transmission problem.  Due to the fact that I get all these channels I would think my receiving is OK. 1, 4, 10, 12, 18, 24, 36 out of Milwaukee and also 5, 7, 9 etc out of Chicago.  I am using a Channelmaster 8 bay UHF with the screen removed to get both Milw. and Chi. at the same time without a rotor.
Thanks

[StarvingForHDTV]

I have never seen anything like what you describe.  A poor signal would cause pixelation and/or audio dropouts.

Perhaps it's your display or set top box or pc card or ??

Good luck.

[bklass]

I think what you are describing is PIXELATION.  I get that too at times.