For what it's worth:
"
Q. What is HDMI?
HDMI (High-Definition Multimedia Interface) is the industry-leading technology and de-facto standard connecting high-definition (HD) equipment, from HDTVs and personal computers to cameras, camcorders, tablets, Blu-ray players, gaming consoles, smart phones, and just about any other device capable of sending or receiving an HD signal."
That's from
HDMI
Redmere is an active technology, not so much an amplified technology as a transmitter/receiver combo that works in similar fashion to HDBaseT, but without the more costly transceivers.
I will say that I avoid Redmere because I don't like the use of directional and active HDMI cables in the pipeline. They are definitely a failure point and since they are electronics, they are subject to potential interference at the electronics level due to RF, electrical, etc.
itschris: Read my review on the Parts Express super slim HDMI cables, they are what you should always be going with in a slim cable at 6' or less:
http://forums.audioholics.com/forums/write-your-own-review/86559-review-parts-express-super-slim-hdmi-cables.html
At the end of the day, I deal with HDMI in the commercial space all the time. It is the standard on which Crestron, AMX, Extron, and others have based their latest distribution systems on in conjunction with HDBaseT. While there are some other 'standards' (DisplayPort anyone?) - It is HDMI which really rules the world on this.
I will agree completely with TLS Guy that it sounds like a compatibility issue between Redmere and something which is causing your issues. EDID, HDCP, or something else... But, with short cable runs, you have super slim HDMI cable alternatives which you should be using. Until then, ditch the Redmere stuff and see if that corrects the issues.