Hi all i'm the following problem

this really is my source code of my index i'm using wordpress 3

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

the issue is it have 5 blank lines prior to the doctype i modified the functions php during my template and absolutely nothing, i'm try removin blank lines within the index and header file. Possess a possible solution?

Use a Wordpress wordpress plugin, like a code minifier (Wordpress minify, etc.). It'll compress your website getting rid of the useless figures (blank lines, tabulations, etc.).

What are the blank lines at the beginning of header.php or index.php inside your theme which are not covered with <?php ?> tags?