You've heard of The Terminator? Now meet The Restorer.
HDMI cables are subject to misbehaving. The longer the run, the bigger the chance that the desired "I" signal pattern is turned into something that looks more like the oscilloscope sine wave that opens classic episodes of "Outer Limits." But you can control the vertical and horizontal, so to speak, with some HDMI extenders. There are several kinds available, from inexpensive inline devices like the UltraLink that worked for Tom (but not for me) and there are more heavily engineered solutions like the Etheral Restorer.
Ethereal spent a lot of time trying to understand what made HDMI fail (and it's a laundry list) and perform what they call line conditioning to the video signal. While Ethereal's Brent McCall will tell you off the record that they can get up to 300' runs from their inline, but externally powered, Restorer. But that's in the lab, so for now, they're only guaranteeing 100' runs. With a 100' of HDMI cable, the Restorer sells for under $750 (exact price TBD).