This is most apparent with the "Mac Classic" theme. When you start with a "<?php" the background is a light gray. This is coming from the "Embedded Source" color. This is NOT supposed to be happening. "Embedded Source" is supposed to be when the file is set to "HTML" and the "<?php" tag is used.
Compare this to TextMate and how it treats 'Embedded Source". The light gray is driving me batty ;).
Customer support service by UserEcho