Strange problem changing to SD channels

[AndrewSmith259]

Sometimes, when changing from an HD channel to a SD channel I get a random channel name appear at the bottom of the screen. If I then change to another SD channel that same channel name stays at the bottom of the screen even though I am on another channel. The only way to remove the channel name is to switch to a HD channel.
I am attaching some photos to try and illustrate what I mean.
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[AndrewSmith259]

Anybody any ideas on this one. The problem seem to occur intermittently but it is quite frustrating when I get the large box in the bottom right hand corner of the screen.