"Style sheet is missing" error message when i upload a theme in WP 3.0

Hi,

I have a WP hosting account at wpwebhost and i just did a install on wordpress 3.0. I was running some tests on the previous version of wordpress with different themes, but i have problems now when i try to use those themes with wordpress 3

for example

I tried to upload those themes :
buddypress-corporate-theme-1.2
Business feature beta
business services beta

Broken Themes
The following themes are installed but incomplete. Themes must have a stylesheet and a template.

Name Description
buddypress-corporate-theme-1.2 Stylesheet is missing.
wp-business-feature-1.0 Stylesheet is missing.
wp-business-services-1.0 Stylesheet is missing.
wp-showcase-1.0