BTW for your screen shot you show the ports as 8338. Should these not be 8333 ? You prob know what you are doing here and I don't think their would be any response at all if the ports were wrong but thought I'd mention it.
I changed it on both the cube and the proxy. I had already tried the default a few times.
As said dunno what triggered it working now instead of the 100 other times I tried. Maybe might want to try starting/restarting the miners at different times then you start your mining proxy program. Like I for example I was trying the cube first and then relaunching the stratum mining proxy, whereas before I was doing this in reverse. Again logically I doubt this would make a difference, maybe it was pure luck, but all I can say is now a hundred false starts later and it is hashing.