BF2S Forums HDTV cable problems. Timewarner.

Alright ive been having problems lately with my HDTV subscription to time warner.  On the HD channels like Discovery and TNT,  the image will abruptly freeze and you could see small box frames all over the image, in short is distorts, same with sound too.  I'm using the component cables that came with the box and the other channels work fine.  + i have the Cable box set to 1080i? could this be a problem since i know some networks broadcast in 720p.  Also the cable from the roof is split. 

Example

**** (electric pole)----------cable---Splitter---|-|--------|   Cable box normal 
*                                                                |  |         |
*                                                                |  |_____|
*                                                                |
*                                                                |----------------------------Cable to HDTV box   
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