I had a new roof put on in 1998, with a 10 year unconditional warranty.
Water is coming in though a window casing. Apparently snow on the roof is
melting, coming in though the roof, coming down the Cathedral ceiling into
the wall, and then leaking through the window casing.
The roofing company says it is perfectly normal "freeze back" and there is
absolutely nothing wrong with the roof.

I have never heard of "freeze back" before. Is it a roof problem that needs
to be fixed?

Last year I had a leak from improper flashing and it took me a month to get
him to pay for the repairs. He insisted I had no warranty despite what the
contract says; so I am not really inclined to trust him now.

Thanks.