Big streaming issues via gigabit LAN

Hi

I have exactly the same problem, and have had for a long time!!!

Here is what I got:

Qnap 509 (latest fw)
Dlink gigabit switch
Dlink dir655 gigabit router
apple tv2 (latest fw)

How it is setup:

Qnap connected to the switch via cable
Switch to router via cable
Router to apple tv2 via cable

Here is what I have tried:

Connect qnap directly to router (not use switch) = didn’t work better
Qnap to switch to apple tv2 (not use router) = didn’t work better
Qnap directly to apple tv2 = didn’t work better either!!

Im just out of ideas, what to do?? I’m just so tired of movies freezing from time to time…

Ps. I’m not saying it’s atv issues, I don’t know, I’m just sayin I’m desperate and appreciate all the help I can get