Sky remote not always working

[Playbill]

Sometimes the remote for our sky+ box wil only operate the volume. Channel changing and all other functions will not work. When this happens the remote will not even switch off the box - but does switch off the TV! We can change channel on the box manualy but nothing else. After a time it seems to rectify itself.
Any one have ideas why this happens and a cure.

[ABerrant]

Wen you press the TV button on the remote it only operates TV functions.

When you press the SKY button it operates the Sky digibox plus the TV volume.

[Playbill]

ABerrant - thank you very much, that does it. Also feel very stupid for not working that out myself!