PLA 5206 Internet Speed Problem

Hi, 

I have got PLA 5206 v2 powerline. When I connect PLA device with Pc case same electric source, internet speed so slowly..

I test it (PC turned off) with laptop; my internet speed is 45 - 48 mbps
PC and PLA connected same electric source; internet speed is 5 - 20 mbps (http://www.speedtest.net/result/7219384599)
PC and PLA connected different electric source; internet speed is above 40 mbps

My sistem properties;

• Tilgin 2331 fiber router ( Internet speed up to 50 mbps)
• Aerocool 500W VX active PFC psu
• MSI A68HM GAMING Amd A68H 2400MHz(O.C.) DDR3 Soket FM2+ mATX
• AMD A10 7870K Near Silent 4.1GHz 4MB Cache Soket FM2+ 
  
• CAT6 or CAT5e cables (Max 2 meter)

I tested PLA device at all wall electric source with laptop internet speed above 45 mbps (PLA devices distance 1 to 15 meter)
I connected PLA devices same electric source internet speed above 47 mbps (PLA devices distance max 10 cm)

What is my problem? Thanks.. (Sorry for my poor English)

#PLA_April