When the DPP lnbf first came out, the software in the receivers did not support these lnb's connected to a DP44. If installed, the lnb's would work briefly, but eventually fail in a short period of time. These lnb's are now compatible with the 44's. In contrast, DP34's and DP33's still require DP Twins or DP Singles/Duals.
The power inserter supplies power to the switch/lnb. Some installers install the DP44 with no power inserter, thinking since it initially works it is not needed.
