interference on TV transmit/receive setups

[#1]

Having just read about interference found on routers , I wonder if anyone has a similar problem with the
wireless transmit/receive bundles for televisions?
I recently setup a similar to an upstairs tv from the tv in the living room.
The sound and picture were reasonably good, except that the picture had interference (low-pitch noise and continuous rolling  bands of lines)
The explanation in the handbook suggests neighbouring , or your own,other equipment which use the same 2.4GHz band.
The shop (Maplins) suggested a much dearer bundle which uses 5.4 or 5.6 (?) GHz.
Has anyone any personal experience?

[#2]

Not personal experience, I use a cable link between rooms.
There was an article in the news recently that some Sky video senders (used in room to room situations) were interfering with certain types of key-less car ignition fobs, leaving drivers stranded. Also suggested that they could interfere with wireless routers as well.

[#3]

Yes   I had considered a splitter at the sat dish cable but the techies have told me that this is not a good idea because
the signal strength would be impaired......
the cable would be split in the loft and a second cable run sent to the upstairs tv.....
A second dual lnb would not be practical because the existing one is already dual (pulling 13 and 19E)