Bought 6 new internal 6 panelled doors from Wickes. First one went on ok but when I drilled out for the latch on the second one I noticed that the lock block wasn't sitting flush with the face of the door but was recessed in about 10mm. When I chiselled out the recess for the faceplate of the latch. the edge of the door started splitting quite badly. Any advice on whether this is a common problem or what I can do about it would be appreciated.