I just received my M1 Slingbox (in Bulgaria). Had some problems figuring out the setup, especially as my ZTE IPTV receiver was not on the list of supported manufacturers/devices. Good thing I found this thread: https://community.slingbox.com/message/96697#96697 from BigVasko (another Bulgarian) who solved the problem by using the Shanghai Telcom IPTV device's remote profile, which although in Chinese, at least has the correct remote signals.
Now the problem is the M1 has no HDMI input and I never knew composite video cable do not support HD signal. Anyways, the problem is that even when correctly switched to this option (and all cables plugged) I still get only black screen. Although the player says "video signal found" the is no video at all. Just black screen and audio.
Downloaded the iPhone app. Almost the same thing there. Only instead of black screen I get some distortions and noise. Any ideas what I am doing wrong?