I have configured FBA Custom login page as described here .
After this, FBA user login is working fine. For Windows authentication, the user is able to login but sharepoint redirects the user to the custom login page frequently while navigating to different pages on site.
The user then needs to click on Windows users login link and he is redirected to whatever page he came from (this time the user need not enter any credentials just clicking the Windows login link is enough).
Any idea how to fix this issue so that Windows authenticated users are not repeatedly redirected to login page?
I checked the hive logs and see this error:
'Detected a redirection but the redirect is not to a known signin page'