Thanks for all your ideas as to how to get the blighters in. Nothing worked but a trip down to the garden centre and a new packet of thingies did the trick. Slightly smaller so went in a treat. Shelves and hanging basket rails are now up. Greenhouse man has just got to come back to fit the pane of glass he broke (ho-hum), fix on the guttering pipes and put on the cresting stuff on the top. (Can't help but wonder whether he should have done that before the glass went in but I presume he knows what he's doing!). I already have a chair in there. DH said he had a giggle because he was watching me from the kitchen window sitting in my bit of peace and quiet. What bliss!!!!