Yes last night, (that is 23.00 in the UK) as I tried a reply to a
message my 10.04 froze, grayed, crashed, whatever you call it and I gave
up again and shut it down via the power button.

I am certain this is not caused by the computer because I have checked
it from back to front.

It is not caused by Gnome, unless there is a drastic change in this
version because all versions before this were OK.