I didn't have that at the top, but I did have a gap within the middle of my script and similar issues within include scripts, I took that all out at the same time as trying out other ideas regarding compression settings within php-5.6.ini and it started working as expected, I have reverted all the other things I did and restarted the server and it's still working so must have been due to the issue you raised. So glad to have it working!
Cheers to the few folk who sent me ideas! Regards Does your PHP source file have a blank line at the top? e.g. [blank line] <?php // send image bytes ?> i.e. your PHP source file has the 0x0a in it? If I'm right then that will be sent as part of the output (the first byte in fact - what you are seeing). Just an idea!