Widget plugin error site warped in IE

I have 2 problems. First, when I try to manage the widgets on my site I receive this error: Fatal error: Cannot redeclare register_sidebars() (previously declared in /home/jasiribl/public_html/wp-includes/widgets.php:15) in /home/jasiribl/public_html/wp-content/plugins/widgets.php on line 22.
I had no problem at first, so I’m not sure what I did to cause this error. Anyone know how I can fix this?

Also, my site looks fine in Firefox and Safari, but in IE it is warped. Is there anything I can do about this?

my site: jasiri-blog.com