Samsung Interference/Handshake issues using baluns

[MosDef06]

I work for a home audio/video business. We have noticed several issues between the new model year Samsung LCD's and Blu Ray players. In many installations we use Cat-5 HDMI baluns to run video signal from the AV receiver to the monitor. We have noticed that since the new model Samsungs came out sometimes the picture "pops" in and out or does not show up at all. Even stranger... in a couple installations the flick of a light switch... or a fan switch... or an HVAC unit kicking on will cause the picture to cut out. This issue occurs regardless of the balun manufacturer. I know what you're thinking... interference because the Cat-5 cables are too close to a high-voltage line. This is what I thought, so we bypassed the in-wall cabling and simply stretched new Cat-5 cabling across the floor, reconnected it to (again, 4 or 5 different well-known balun manufacturers) and the SAME result happened every time. We also achieved the same result if we bypassed the AV receiver and hooked straight to the TV using the baluns. We even switched the wiring to Cat-6 to give us the best possible resistance to AC interference to no avail. This is troubling because we liked the products Samsung had to offer and are looking at abandoning it all-together... to say nothing of customers and quotes hanging in limbo.
On another note, if we change the blu-ray player to LG... the problem disappears. Has Samsung gone cheap and gotten rid of some video shielding? Or is it a problem with the baluns not keeping up to date with the latest HDMI versions which may be available now in Samsung models and not LG?
Any help is appreciated... we are scratching the skin off our heads on this one. Needless to say, Samsung won't be of much help.

[rbinck]

Have you tried using a HDMI cable as a test? That could eliminate some possibilities.

[MosDef06]

Yep. It works fine with an HDMI cable. The issue is distance from the equipment to the TV. In many installations, either the distance is too great for a factory cable, or a cable of that length wouldn't be cost-effective.

[rbinck]

I understand and have had many installations using the baluns. Key Digital is the brand that I have had the most success with. With the fact that there is no problem with a standard cable, I would be trying a HDMI repeater at the source. They boost the signals which may provide enough extra to get past the noise threshold. I would guess the one player has a slightly lower output level than the other.