I always fit the base units first then the wall units. Often even the work tops go in before the wall cupboards as there is not room to fit afterwards. Basically it is easier to line everything up too, and if you put the walls up first, you will be banging your head on them.
If your kitchen plan includes a full height larder unit, fridge/freezer or tower oven, these have to be fitted first so as to be able to get not just the wall cupboard position but their height above the worktop.
no nothing like that , just a few units either side of the extracter , but found out now that the wall is a mile out (vert) so stumped as how to fit anything on there now , plasterers coming back tomorrow to look at it , i thought that was the whole idea of battening the wall was to get it right , i know the corners arnt 90 , my other question sorted that out