Hi,
I have removed the Lan card, re-flashed the Bios with the F8 version, as suggested by Gigabyte Support, used the optimised settings (but disabled the floppy drive) and lo and behold it now works!!!!
I have switch it on and off about 10 times now and all is well - fingers crossed.
But what I can't figure out is that I tried all the things above before, some more than once, and it didn't solve the problem then but it has now.
Hopefully this is the last post on this issue.
Thanks for your help to those who replied.