I have a SQL DB with GIF data field. f.ex there are 2*27006 bytes in there (hex strings). I can retrieve them without any problems but when I do

  $fp = fopen($fn, 'wb');
  $Bin = ConvertToBinary($GIFString);
  $BlockLength=strlen($Bin);
  set_file_buffer($fp, 0);
  fwrite($fp,$Bin);  
  fclose($fp);

$GIFString has the correct size of 2*27006,
$Bin has the correct binary size of 27006.

But the file has the size of 27176 bytes. I have no idea where the addiotnal 170 bytes are coming from (doesn't help when add the $BlockLength to fwrite). After 0x363 there is a 1 byte shift etc...

regards
Jay