You won't have any luck using a DP34 in place of a legacy SWxx switch unless you are replacing the LNBFs at the same time. DishPro and Legacy are not compatible.
I've tried all of the different port configurations and none seem to work. I finally hookied up my original SW21 switch and hooked it up to my 510 and it is working. So I know I'm good from my LNB to my switch and from my switch to my receiver. I guess the only thing left is the switch. Should I stick with the DP34 or get a SW44 or SW64?
If I'm not ready to change my LNBs at this time. What switch will give me the maximum ports out?