My Wp site went blank after upgrade to 2.9

Please help…

I backed up my blog, then I upgraded to the latest version of WP.

My dashboard is fine.. all my posts are there.

The only problem is that my live blog is blank.

I see this is the dash:
Broken Themes

The following themes are installed but incomplete. Themes must have a stylesheet and a template.
Name Description
category-icons Stylesheet is missing.
different-posts-per-page Stylesheet is missing.
global-translator Stylesheet is missing.
please-link-2-me Stylesheet is missing.
post-plugin-library Stylesheet is missing.
random-posts-plugin Stylesheet is missing.
smart-youtube Stylesheet is missing.
video-widget Stylesheet is missing.
wp-polls Stylesheet is missing.

I have no clue what to do. This is a custom theme I don’t want to lose.

What should I do?

Thank you.