Missing EPG - Never used to be missing

The EPG has been working great via OpenTV-SkyUK for the past few weeks but it has stopped working for a number of channels.

The ones I have noticed are...

BBC One HD
BBC 2 England
ITV 1 HD
Channel 4 HD
Channel 5
Some of the ITV2,3,4 and +1s
BBC Three
BBC Four

I'm running - HTS Tvheadend 3.1.773~gc74b0cf~precise

I think this is the latest prebuild available?

Has anything changed to cause this?

Most other channels EPGs are working fine, I think all encrypted channels (SkyUK) are being pulled in great. Just a number of FTA channels now have a missing EPG where they previously were filled for 7 days.

I've tried deleting the epgv2 db file. This looked to have cleared the EPG and all the channels except the above filled up as previously.

Any ideas?