[Plugin: All In One SEO Pack] someone please help me with all in one seo pack

I deactivated my all in one seo pack and realized it took away my titles that I needed, so when I went to re activate I get this error:

Fatal error: Cannot redeclare class All_in_One_SEO_Pack in /home/advanc34/public_html/blog/wp-content/plugins/all-in-one-seo-pack/aioseop.class.php on line 3

I updated the plugin also and it still does this. Please help.

Thanks in advance!