Why do I have to re-boot my Thomson DTI 6021 everyday to receive?

I had my loft insulated this May with Celotex. This blocked the signal to the arial, which is in the loft.
I removed one section of the insulation next to the arial and re-instated the signal and reception was fine. I don't think this has anything to do with the following problem. For the last couple of weeks I have had to re-boot (off/on) the box every day to receive a signal/TV reception. Also, once the TV is receiving, the information box on each channel has no details and is 'Undefined'. Can you help?

Regards,

Jos.