Consider upgrading your cable. I had a hand created RG6 based set of RGBHV cables I had been using for my CRT projector. When I changed over to my Sharp 10k, I reused them and was really unhappy with the clarity. Granted, I had a 25' run, but still. Electrically & mechanically, the connections were good (I make a lot of cables and do a fair amount of testing, so I have at least some confidence in them).
I went to BetterCables.com and got the silver serpent reference line. The result was really, really remarkable (like night and day). It hurt to pay for those cables, but again, the result was spectacular.
On the shorter cable runs, consider higher quality cables too. Originally, I had my Sony 300 DVD player going to my 10k over that BetterCables cable and was thrilled. Then I added a HD cable box and wanted my pre-amp (a Rotel 1066) to switch the component (I didn't want to run two component cables to the projector).
Running the DVD player into the preamp and then to the projector created quite a noticeable degradation of the signal I put the fault on my preamp, but everyone I talked to said that Rotel component switching was very good and shouldn't introduce any artifacts. Then they suggested the cables might be at fault.
I scoffed at that - I had 1m/3' monster component cables from the player to the preamp - there was no way such a short run with a reasonable (though not great) cable brand could cause this. But, after two weeks of trying, I finally decided to test this out and ordered a 1m/3' silverserpent from bettercables.
Well, as you are probably already suspecting, all the noise and crap in my picture went right away. In fact, with the signal going from the DVD player to the prre-amp and then the projector I could not see any diff in picture vs a straight DVD->Projector run.
I am *not* a fan of expensive cables. I honestly think that for regular audio signals, a reasonably good cable is more than enough. For speakers, 12 gauge stranded copper is fine. At the very low frequencies audio operates on (relative to video), these are more than fine and all the extra stuff is, IMHO, a waste.
But I am now a believer on using quality video interconnects - especially when routing HDTV class signals around. BetterCables was a good company to deal with and their reference line are pretty nice. You may get the same from a less expensive cable and it's probably worth checking it out. For me, since things were so bad, I decided to start "at the top" and once the result was so great, I didn't want to risk going back