If you are "including" files, then that might be the problem.
For example, the preview window is not actually "called" from the same file location as the actual file. (because the file isn't actually saved since it's just a preview.)
So let's say you have something like this in the file that you're editing:
<?php php include("path/to/some/include.html") ?>
Now.. the problem is that IF your file is located in some subdirectory.. then this include command is going to be "relative" to the actual file location where it is called.
But since the preview is located in a different folder... the included file won't be found.
I think that is the problem.
The solution is to use an absolute path when including your file. Like this:
<?php php include("/home/account/full/path/to/some/include.html") ?>
Let me know how that goes.
