Problem with fmod() function

Hello, My understanding from the documentation is that the fmod() function should work with floating point numbers however the following snippet of code: <?php //php 4.3 on Linux $x = 1.05; $y = 0.05; echo "x: $x <br>"; echo "y: $y <br>"; echo "fmod: " . fmod($x, $y) . "<br>"; ?> outputs the following: x: 1.05 y: 0.05 fmod: 0.05 I would have expected to get an answer of 0 i.e. no remainder. It works fine for whole numbers. Can any one shed any light on this please? Thank you. Regards, Andy P.S. I tried using the following function but I get the same results: function fmodAddOn($x,$y) { $i = floor($x/$y); // r = x - i * y return $x - $i*$y; }