Losing Signal from the 101 ,But only on the d11's. Thats strange! Do all your receivers, have a wire running Directly to the Slimline, Or do your receivers connect to a Multiswitch? "My guess would Be a Multi switch, Since 3 SD receivers an 1 DVR would be 5 wires, But you never know."
What part of the country do you live? Cold, Hot? Are you Sure your HR-21 is working fine with the 101?