Page Not Found – Lost Page!

my second page comes up as “Not Found Sorry, but you are looking for something that isn’t here.”

i recently changed the archive.php as suggested in another post to get rid of the words “archives” :

<h1 class=”pagetitle”><?php printf( __(‘Archive for category %s’, ‘arclite’), single_cat_title(”, false)); ?></h1>

to

<h1 class=”pagetitle”><?php single_cat_title(); ?></h1>

i changed it back to the original but the error is still there. pretty sure i didn’t change anything other than this.

any suggestions??