I tried to do a HDR in CS5.
seems to be progressing ok with the layers palette visible when suddenly everything vanishes - I looked online and a comment was to reset preferences - but I don't know how to do that.
It also wasn't clear if preferences for CS5 only or for the whole system needed to be reset.
update: have been looking online -I managed to delete the preferences file and completed one HDR OK.
However same thing happened on second HDR - bit rubbish if I have to delete the preferences file between HDR's