when using the fwrite with
php4apache2.dll module enabled.  It seems to write corrupt binary(PDF) files.  I was using it with the ROS class
http://www.ros.co.nz/pdf/ to write PDF files. 

When I changed the apache 2 server from using php4apache2.dll to just using the cgi php.exe it was able to write these files just fine with no corruption.  I think something may not be working properly in the dll as it pertains to the fwrite function.  

I am pretty sure the error did not involve the ROS library as I was able to output to the screen with no problems with that library using the php4apache2.dll or php.exe.  It was only when I tried to write it to a file with fwrite that the problem occured.  This is the code I used for writing the document in case you need that.

$fp = fopen($fdirandname,'w');
fwrite($fp,$pdfcode);
fclose($fp);

I was using Apache/2.0.43 Windows XP Professional with SP1 installed and PHP 4.3.0 (the binary install version from your website).

I hope this helps. If you need any further info please email.