I got a SIR-T165 unit on ebay, but for some channels it goes into
a continuous reboot cycle, and I am suspecting this is because it needs the
broadcast firmware update.

I called Samsung, and they want the unit sent in, but I searched around, and it seems there was a downloadable firmware update at some point. Does anyone have it? My email is drapati at yahoo dot com.

Thanks in advance.

Downloadable? I don't think so. Way back when, they sent out a kit that contained a cable and a CD with the software on it. I still have mine for the T-151 somewhere. IIRC, the update resolved the rebooting issue whenever the box encountered 5c copy protection. That said, I can't recall if your box and the 151 had the same issue or if the update package contained software for either. I'll look for it.