HDMI to DVI problem

Hi all, I wonder if you can help. I have just installed a new Panasonic DMR-BS750 which works fine apart from two problems which I don't seem to be able to get round.
1. The TV I have is a couple of years old (Philips HD ready FlatTV) and only has two SCART and one DVI ports and no HDMI. I bought an HDMI to DVI cable and think I have done everything right but the image does not go through to the TV so that I am reliant on a Scart lead, which is not great and stops me getting HD, which was kind of the point.
2. (and this may be related) The unit is showing an error code F5 all the time and I can't seem to find out what this means. IS this related to the lack of image via the HDMI - DVI lead or something different?
I am tearing my hair out - what little I have left.