first line of php file off by one

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I'm using mod_layout (2.5) in combination with php (4.3.3) on an
apache (1.3.29).

My problem is:

PHP pages get delivered with an extra empty line at the beginning.

So I'm unable to add a line <?xml version='1.0' encoding='ISO-8859-1' ?>
as the very first line. But e.g. http://jigsaw.w3.org/css-validator/validator 
insists on this line to be the very first to detect the charset correctly.

Of course, to be able to use "<?xml" in a PHP file I have to disable
short_tags in php.ini, which means I have to switch to "<?php"
statements instead of "<?".

The problem doesn't occur with non-PHP pages.

Any hints?

Albrecht
- -- 
// Albrecht Gebhardt          Tel.: (++43 463) 2700/3118
// Institut fuer Mathematik   Fax : (++43 463) 2700/3198
// Universitaet Klagenfurt    mailto:[email protected]
// Universitaetsstr. 65       http://www.math.uni-klu.ac.at/~agebhard
// A-9020 Klagenfurt, Austria
// GPG PK: http://www.math.uni-klu.ac.at/~agebhard/agebhard.asc
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