NEC VT660 wont display using 5 core RGB HV cable and Asus Z91E/Ergo Ensis S

I am using a large number of NEC VT660 projectors and connecting to them using an RGB HV cable which is being converted from D-sub to the RGBHV and back to D-sub. This cable works fine on my laptops but doesnt work on the Asus Z91E machines we have. If I use a standard VGA cable it works fine but with the RGBHV cable it does not.

We use the RGBHV cable because we can get greater distances. If we put a booster on the cable it works fine. The booster however causes problems on our other machines.
We have tested using a splitter, we terminated one leg of the splitter but this didn't help. We put a Telex P600 on one leg of the splitter and the NEC VT660 on the other and we got a picture on both projectors.

If we connect the Telex to the pass through of the NEC we get a picture on the Telex but still no display on the NEC.

I'm thinking we may need to put greater resistance in the terminator we tried on one leg of the splitter or something like that or that there is a grounding issue.

Problem only with NEC projector, RGBHV cable and Asus Z91E

any thoughts please.