Thinking that its probably time to get another main board. Talked to the local shop, they have batteries but say they don't think the symptoms could be due to failing battery. I can try but its so intermittent. The latest thing that happened, it crashed three times on Saturday, once restarting itself quite normally. I have been checking temps using gkrellm thinking maybe the thermal paste had deteriorated - they are 33 and 32C on the two cores after about a half hour working this am.
One of the crashes on Saturday was with only the bios screen open. Simply died. I was looking at the temperature at the time: 49C cpu, 50 PCH (whatever that is!).
I am thinking of an Asus board and an i5 processor - the old one is socket 1156 so the whole lot has to be replaced.. Ouch!
The Gigabyte screen when it does the delayed boot shows Boot Record, and then it shows a little table, success 1 2 success2 4 success3 4
Don't know what this means. It also offers you a choice of last good and default.
Al