How do I recompile PHP --with-gd using the bundled GD library?

I have installed Drupal 7.0-alpha6 on Ubuntu. But when I went to Reports/Status report, I found a pink-colored area categorized as "GD library rotate and desaturate effects 2.0 or higher" and having the following message:

"The GD Library for PHP is enabled, but was compiled without support for functions used by the rotate and desaturate effects. It was probably compiled using the official GD libraries from http://www.libgd.org instead of the GD library bundled with PHP. You should recompile PHP --with-gd using the bundled GD library. See the PHP manual"

I tried to follow some instructions in web sites, but never got the above error message changed. I had done "sudo apt-get install php-gd", “sudo apt-get install php-common” and “sudo apt-get install php-mysql” before Drupal 7 installation. Were there any thing wrong with these installations?