HDTV reception works on some TV's, but others.....

[riverpine]

I tried to figure this out and I'm stumped.

Short and sweet version: HD antenna (no cable or sat.). Antenna line is split: one split works fine on the main HDTV - all of the expected channels come in fine. One split goes to a DVR right next to the HDTV. Some of the channels work, but some several are "blue screens." The DVR is the same distance from the antenna that the working HDTV is located. One other split goes under the house and comes up elsewhere. I get the same "blue screens" on the same channels as the DVR.

To make it even more wierd, before the official final HD transition date, I got all of the channels on both TV's and the DVR. But when the final deadline passed, I lost several channels.

Any ideas?

Thanks.