ok, I have a Delta shower faucet that I installed in the basement. Now Im ready to actually put the corner shower kit together but I have one major problem, the screws that hold the flange (escutcheon) to the shower valve will not screw in. I tried screwing thenm in and they barely go in and then will not turn. When I pulled the screws out it looks as if the threading is getting messed up. How can I fix the threading on the valve so that it wil accept the screws? Please dont tell me I have to replace the entire valve. Thanks for any help in advance.