Mac not streaming over WIFI

i have a macbook pro connected via my wifi to my wdtv live which has a buffalo USB wifi dongle. i have tried all firmwares up and down and now i’m on the latest firmware. my settings in the macbook pro are as per wdtv live’s instructions. but i just can’t stream any video. it seems to get stuck after i select it. even navigating through my macbook pro’s folders on the wdtv live is sluggish and it crawls. please help. the problem has only gotten worse and i have no tech support on this product in india.

What is the exact model number of your adapter and what are the codecs of the media you are attempting to play?

Lawrence there’s been a curious update of sorts. I shifted the Buffalo wifi dongle to the top end USB. I don’t know if it’s USB 1 or 2 . I think it’s USB1 as my external hard drive shows up as USB 2. Suddenly it started streaming quite well. It played an mkv file of 2gb but when i tried to play a .vob folder it started stuttering and the audio went off. Ever since it doesn’t play with audio. Then I read about a mac app called Playback. It somehow plays flawlessly with that. Streams everything. You asked about formats i tried: mkv, avi, mp4. When the wifi dongle is attached to the rear USB 2, where the HDMI and power cable go in, it navigates sluggishly to the file and then…zilch. It just keeps on showing the rotating sign. I don’t know if something’s wrong with the USB port. It definitely isn’t streaming with Playback or directly from my mac without playback initialized.