HDMI cable issues

[vdherik]

Hi guys,

Current setup:

RPi <<1m hdmi cable>> AMP <<1m hdmi cable>> TV

For an upcoming renovation the RPi will be moving further away from the rest (it will eventually be replaced by a home server with XBMC), so I've replaced the cable between RPi and AMP with a 10m (30 ft) one.
Now, some (!) video files won't play anymore. The amp will either switch back to PCM or loose the audio signal altogether, and the TV will eventually come up with a "unsupported video signal" (or similar) complaint.
I'm aware that 10m is stretching the limits of HDMI, and this probably isn't the best quality cable either. And yes.. plugging the old cable back in solves these problems.

Still, couple of questions remain:

- If this is (very likely) a cable issue, why would only some files fail to play, where others still play fine. File size/format doesn't seem to be a factor here.

- Is there some way to debug this further (like hdmi handshake) to see if there's any difference with the different videos?

- Would these problems be likely to persist once the RPi is replaced with a dedicated server running XBMC?

- Any other suggestions (besides the obvious "don't change the cable")?

I've also tried "config_hdmi_boost=7" (and other values), but no change there.

Thanks!