A friend of mine reads all of his books... and said he was in a slump there for a bit... but here recently he seems like his old self again. Maybe between that... and the fact that I am sure you can never make a movie to come out as good as a book anyway... maybe that is why so many I know don't think his movies are as good as his books.
But then for someone like me... who hasn't read the books... maybe that lets me enjoy the movies that much more.
As for Secret Window... he has an OMB credit in profiler... according to wikipedia...
It was written and directed by David Koepp, based on the novella Secret Window, Secret Garden by Stephen King...
so maybe you can find it and check it out.