Mkv Issue

I recently bought a WD tv live, but I have problems while playing mkv files.

My system:

iMac 27", 16GB RAM, i7, 256GB SSD, 2TB HDD with several mkv stored in it.

Router Netgear wi-fi  WNDR4500

The signal is full both on Mac & wd tv. The router can support 5MB/s transfer speed between devices, tested with iMac -> MB Air connection. So the router can fully support HD transmission: I can smoothly play a mkv (even >40GB) on my MB Air reading it through wifi connection. 

Yesterday I was watching a 16GB mkv on my TV and it played smoothly for 25 minutes, but suddenly it began to reduce the frame-rate, and the film became unwatchable because every 2 seconds, it stopped. I tried to restart the film, even from the beginning, but the problem was still there: every second there where dropped frames. 

Can anyone help me? 

An “Average” of 5MB/sec is HARDLY sufficient for streaming HD media.  

HD media requires up to 40 megabits per second – UNINTERUPTED.

Your MacBook can probably do better because it buffers so much more media.

The film I was watching has this specs, as you can see the bitrate is around 15 megabits per second: 

Name : nwoteht80.mkv
Data : 23/01/2011 13:34:12
Dimensions : 16,091,066,117 bytes (15345.636 MB)

[Info]

Lenght : 02:04:45 (7485.12 s)
Type : matroska
Stream n. 1 : video (V_MPEG4/ISO/AVC) {The Town}
Stream n. 2 : audio (A_DTS) {English DTS}
Audio streams : 1
Muxing Application : libebml v0.8.0 + libmatroska v0.9.0
Writing Application : mkvmerge v3.4.0 (‘Rapunzel’) built on May 15 2010 09:38:20

Resolution : 1920 x 800
Width : multipla di 32
Height : multipla di 32
DRF : 21.690256

Codec ID : V_MPEG4/ISO/AVC
Resolution : 1920 x 800
Frame aspect ratio : 12:5 = 2.4
Pixel aspect ratio : 1:1 = 1
Display aspect ratio : 12:5 = 2.4
Framerate: 23.976024 fps
Stream size : 14,257,103,731 bytes
Time : 02:04:44 (7484.101385 s)
Bitrate: 14714.883049 kbps
Qf : 0.413821

[Audio]

Codec ID : A_AC3
Channels (contenitore): 1
Frequence : 48000 Hz
Stream size : 419,166,720 bytes
Bitrate (contenitore): 448 kbps
AC-3 frames : 233910
Time : 02:04:45 (7485.12 s)
Bitrate (bitstream): 448 kbps CBR
Mode : 3 front, 2 rear, 1 LFE

Agreed… but that’s an overal average…  You’d need to know what the peak bitrate is.