Ok, u need to understand one thing, i dont know what your settings are set to and why you are expiriencing the problem you are reporting but watching HD Movies on Cable TV/Sattelite is never problem free as in a "PERFECT" picture such as blueray because quiete frankly these crappy cable and Satelite companies are compressing our signals which makes some stuff really ugly and unwatchable with artifacts, i watch only HD channels and i like it alot on my 52" a650, with AMP set to high i love how everything looks.
picture being so so on sd channel is normal , on other tvs its even WORSE , i had the A550 , god what a horrible expirience that was, i enjoy watchig SD now on the a650 More than it was on the a550 but still it sucks, it was unwatchable on the samsung a550 though, for me atleast.
You seeing blurry images IS NOT normal, it might be that you have a defective set according to your description but im not sure. i dont see any bluriness like u describe.
Tell us more but just so you know, no other TV will give you a better PQ if thats what ur after because if ur done ur reasearch, the a650 is a top notch TV, compare any set to it, i did, cant find a better one out there at this moment and quiete frankly im not looking for any any more either
maybe some plasma will but thats a plasma, not an LCD..
do you notice these problems with a PS3/XBOX360?