Hello. This is my first post. We're currently building our house and recently had 7 of the white pvc velux windows fitted. This weekend I noticed a crack around the top mounting plate on a window so checked them all and found 5 that are all cracked the same. Velux told me this morning and sent an email that it's a known issue and would send new windows out which I would have to pay to be replaced.....which I disagree with. They now say its not an issue, they were fitted wrong and the email saying it was a known fault fault shouldn't have been sent. Has anyone come across this problem before........thanks