HDMI Splitter / Multiplex Cablevision Cable box to multiple TVs.

Does Cablevision block the use of a HDMI 1x4 multiplex / splitter to multiple TVs and how?

I purchased the following HDMI splitter over Cat 6 to display the cablebox HDMI video to multiple TVs through-out the house. It worked great for several days. Then the cablebox did a unannounced "Reboot" while watching TV and now video is blank when going through the HDMI 1 x 4 multiplex. I tested the mutiplex by hooking it up to another HDMI source and everything is working fine and of course the cablebox works fine on the HDMI out when connected directly to my TV. When I hook the cablebox back to the multiplex, a blank screen is displayed.

http://www.monoprice.com/products/product.asp?c_id=101&cp_id=10113&cs_id=1011307&p_id=8159&seq=1&format=2

I have been running the cable box directly to my AV receiver then to the TV for the last two days bypassing the HDMI splitter as I work on researching this issue.

Note: Yesterday the cable box rebooted again with no warning. Prior to the cablebox reboot two days ago, everything was working.

This morning I hooked the cable box to the splitter exactly the way i had it configured when things stopped working. My primary TV (TV1) is connected to my AV receiver then back to the spitter for cablebox signal. TV2 is connected directly to the splitter. Everything is working with no changes. I tried to reproduce the problem by leaving both TVs on and AV receiver on before turning on cable box, but was not able to reproduce occurance which is odd. Two days ago I had a blank screen / no video no matter if TV(1) was on / off, TV(2) was disconnected from the splitter. I did verify the splitter was working by hookikng up my DVD player to the splitter when I was getting the blank screen and that cablebox hdmi out was working by connecting the TV directl

I am going keep running the TV from the splitter and monitor for the next occurance of the blank screen / no video issue.