After 12 months of faultless behaviour I think the HDD has gone in my 520HS. After a week away and about 50% disk full the recorded programmes after a certain date where "sticking" eg it would play then would pause maybe for a second or two and then continue but sometimes it would lock up - eventually stopping playing. A rebooted a few times and in the process have lost the EPG guide. It is greyed out and says "The Hard Drive information is incorrect".

Any ideas?

If it is a HD replacement, it looks significantly cheaper to buy a bigger model and upgrade. Can you download the firmware CD (curently running V3.34) or data DVD from anywhere? Have the service remote on my Pronto and confirmed that it works?