Not sure why it is doing it but you could multiply $blocksize * $blocks to get it. It may have something to do with using 32-bit signed integers but it's not a pow of 2, it's slighly more than 2^31. Weird.

For fun sake, try initilizing $size with a float and see if it works after that. I belive if you initilize it with a float, it will stay a double precision. If it works then I would think it would have to be overflowing the int.

-Lee

"To be civilized is to deny one's nature."