I was hacked several times by the "this code for global bot statistic" hack: (see Meandyouis.Us for more information.
I reinstalled everything but my INDEX page was still blank.
SOLUTION: Choose a different theme. ---
I had reinstalled, did a auto-reinstall from within the control panel, but still my index.php page was completely blank.
I'm on Godaddy using PHP4, with WP 3.2.1 and the "Lightword" theme was the previous theme. I don't believe my site was hacked through the Lightword theme, but I think there was a cached file. (No cached files in the Wp-content directory though)