I have an XL4 and have always used hardwired Internet going through an Apple Extreme. Now, with two minis I enabled MoCa and my Internet is crawling although the MoCa is working on both boxes. From the wall Comcast installed a 3 way splitter, one goes to the Comcast Modem, another to the TiVo and the third use to go to another TiVo but is not hooked up. Can it matter that the same cable outlet that is being used to go to the input of the modem is also feeding to the XL4 and therefore feeding the MoCa back into the outlets? I called Comcast tech support and they did something last night that brought the speeds back up. However, this morning speeds are down and I am getting 2mps down and 4mps up with MoCa enabled. I turned the MoCa off, made no wiring changes and am now getting 25mps down and 8mps up. Any thoughts?