Trial Version is better

Why is the Trial Version of Diablo III better than the acrual game?

I have a very fast internet (I live in Bulgaria - one of the fastest internets in the world). I download things from my local torrents and PirateBay with 13 MB/sec but when I play Diablo 3, I got a HUGE lag - 5-6 sec abilities delay.

I havent exp. this on my Trial Acc and the game was smooth. I just bought D3 and I didnt even finished the Trial “thing” (before the Skeleton King) but my game is so laggy…

Is that normal for Single Player game?

PS: And why I cant post in “General” forum? I bought the game but I only have access to “Console Discussion”. I play on PC.