Roof Leak on Duetto 2005

We seem to have a return of an earlier problem where the additional moulding on the Duetto where the front roof light is located, leaks water into the van. This originally happened when the van was about 18 months old and was returned to Autosleeper under warranty and fixed. It seems that this panel was not sealed properly. Since then it has been fine until we just found evidence of a leak again. It appears to come into the van from this panel, runs along the topside of the interior roof panel and has run out to the gap by the interior trim quarter panel by the front roof storage cupboard.
Has anyone else experienced this problem?
Any information would be useful
Regards Geoff and Julie