Unable to tune a particular channel...

[TNT]

Hi guys, just checking: for nearly two years I use the AS2 with DVBV (GE). In Czech Republic so far only one mux broadcasts regularly (ch 25/506 MHz) and two (ch 46/674 and 64/818) are in experimental stage. In 2004 I could receive all of them in very good quality. Then the ch 64 lost its temporary experimental license and stopped broadcasting. It was restarted lately (2 weeks ago) on the same channel but I can't tune it... Meaning when I open the TechniSat Setup4PC and add the channel into the list and try to tune it, it remains red and receives nothing. It is broadcasted from only one place here in Prague now, which lies some 3 km from the antenna of ch 25 which I receive with full signal and BER 0. Both these sites are north from my location and some 10 km away - I even have a direct visibility of the antenna of ch 25, since it is the highest tower in Prague. The output of the transmitter of ch 25 is 5 kW, the one of ch 64 I do not receive is 25 kW. Do you think it is possible that under these circumstances I could be in a "shadow" which does not allow the reception of ch 64 or is it more likely a problem of my AS2???

PS - sorry fo my descriptions, I studied economics...