Is it possible to have terrestrial interference?

[armrh]

Hello everyone,
I just moved and I had always done my satellite installations with success.
Today I installed my directv dish, but could not get an stable signal. I get 94% on 101, transponder 1. Then as soon as I exit the signal meter screen, the signal drops to 0%, then I go back to the signal meter and it is 0%... then I move around and suddenly its again 94%... but then drops to 0%... I tried with different receivers with no success, different RG6 cables and nothing, different BBC filters and nothing... connecting the receiver directly (no BBC filters) and same results. Or If I try different transponders the signal drops to 0%. I also tried moving the dish to another position as well as the receivers with no luck.
I am in the roof of a 6-floor apartment building.
A neighbour tried to subscribe to *E but they refused to make the installation because they could not garrantee the signal quality.
I said what the heck, I can do it with my DirecTv, and my Own RG6 cable, but I was unsuccessful.
Or did I damage the LNB when I moved? I was careful with that, directv is my life!.
Its an Slimeline dish, AU9 LNB.
Any Ideas?

[boba]

Can't see what you have done but first guess is you aren't aimed at 101.

[jdspencer]

To verify reception from the sats, tune to chs 490-494 to test 101, 119, and 110. For the 99 and 103 sats, tune to 480-483.