Playing audio or video from a NAS

I have a NAS (Network-Attached Storage) on which I store all my MP3, videos and data. I am able to play the MP3s and videos from my Acer (using wi-fi) without any problems.
With my macbook, MP3s are really choppy as in 15s of audio then a pause then another few seconds etc. and forgot about even trying to play a video.

Now, I have checked the wireless speed of the router and all seems fine. I have tried to play MP3s with VLC, iTunes and Cog. VLC is the worst (very choppy), iTunes is fairly choppy and Cog is the best (it may pause every second song).

Any ideas as to what could be wrong? Is there some network buffer issue with AirPort?

 

So I decided to run some tests for myself. I use MenuMeters to monitor the bandwidth used to transfer data to and fro the MacBook and NAS. With the Airport card it transfers a 10MB file at 500KB/s either way. When I plug in the ethernet cable, I reach 900KB/s only once touching 1MB/s. There seems to be a constant fluctuation in speed. ex. 500 - 20 -130 KB/s.

Now I tried moving the same 10MB file with my Acer laptop. When the ethernet cable was plugged in, the file transfered so fast that I was just able to see it reach around 6MB/s. When I tried it with wi-fi, it was really fast too.. I think I saw 4.5MB/s.

So, it seems like the Netgear router is fine as well as the NAS. I turned off the Interference Robustness setting in Airport and thats how I got the above greater speeds... before that I could barely hit 150KB/s.

What do you folks think? Is this an Airport card related issue? I really hope not. If so, I'll be really disappointed with my first Apple as I just got it back from the Apple Store as they replaced my logic board due to the digital out always being on.

 

So here's another update to my problem.

I installed Leopard over the weekend hoping that this may solve my problem. It turned out what with Leopard I was not even able to connect to my NAS. I had to enable FTP to transfer files back and forth. So obviously Leopard was removed the next day and Tiger was back. Seems like some of it works fine now. My MP3 files play without any problems. I have tried a few video clips and they play a bit choppy regardless if I use Quicktime or VLC.