I am using the latest version of DNN and I have a custom skin with containers installed in the correct places.

The page renders correctly and the content modules populate on my pages as expected.

For some reason however, I cannot log into the website unless I forcibly cause DNN to flake out and use the default Gravity skin. (I do this by renaming the skin ascx files to some other name that DNN can't recognize).

It appears that DNN won't let me login however with my own skin. It keeps saying:

Login Failed. Please remember that passwords are case sensitive.

But when I use the exact same credentials with the gravity skin, it works.

What gives?