Choppy playback over wlan

Hi,

I am new to Mac and I am learning new stuff every day. I am working as a sys eng with Win and Linux on an everyday basis professionally.

I can play any video over samba (divx, xvid, mkv, ts, mpg etc) without any problems on any Win7, XP or Ubuntu laptops I have.

My setup is as follows:
D-link DIR-655 with 11n only enabled over WPA2 and AES.
Samba running on Ubuntu 9.10
Apple MacBook Pro - 2,66GHz DC 4GB 320GB DVD±RW 13" with the 10.6.4
Driver on wlan nic is 2.3.8b2

The current wlan speed according to network utility is 144 mbit/s

I have tried with
VLC player (worse)
Quicktime (better) (divx7)
Playing movies locally is fine.

Update:
I now tried nfs with the same bad result.

I really hope someone can help me out.