As dennisj00 mentioned, there is a known issue with the HR24-500's and GenieGO.
For the sake of testing something, can you power down the HR24's, then disconnect the coax from each so they have no network connection. Do a 30 sec reset of the GenieGO box. Wait till you have all 3 blue lights again.
Then try streaming a show to the Tablet or iphone from the HR44. Any difference in performance?
The genie dvr is new and had no recordings yet so I recorded a show and it streams to my tablet and plays perfectly with no buffering with the 2 hr24-500's still hooked up. Yea! So I guess it is a problem with the 24's. Like I said I can see all the recordings on both 24's and it will stream with buffering from one but a recording from the other 24 won't play at all I get the message that the dvr is busy try again later but it is not busy. I also have the geniego app on my computer which is hard wired and it buffers from one 24 and won't play from the other even though it is hard wired. The 44 plays fine.
Hopefully directv will find a way to get the 24's to work streaming.
Thanks for your help.