So with all things weighed up I think that...
The first time they fit the shower enclosure tthey didnt put the secondary seal around the tray prior to uprights going in, as shown in the picture below (Which is part of the PDF from the bathstore regarding my shower tray!) . Even if they didnt go around all the tray they should have definatly done behind the uprights.
& to make things worse they have put the wall tiles far to close to the shower tray so that the sealant cannot stretch as it should in the small gap behind the uprights.
Its OK on the bit that is exposed inside the shower the tiles to tray as I could put plenty on and overlap tray and tiles. but for behind the uprights I couldnt overlap as much, as the uprights would, and indead probably have, disturbed the Silicon there.
Also they "Buttered" the tiles rather than spreading adhesive on the walls so that will leave spacees behind the tiles!
Not looking good is it.
Anyhow thanks for all the replys guys...Appreciated.