Yea,im facing the same problem with the new sharp aquos,it interferes badly with my Astro remote,the symptoms are hard to change channels,astro decoder not responding with the remote,the light on the remote stays blinking.I realised that sharp had interfered with my astro decoder when i tried switching off the tv and change the astro channel with the remote and it's working perfectly without the tv running.
However,we can try to resolve this problem by switching off some settings in the sharp tv.first u can try turning off the OPC features(optical picture control sensor).You can try this approach first,then u give me the feedback.