Comments not working

Hello,

I’m working on a theme for wordpress, and cant make the comments to work.
The problem is that, when completing the Name, email, website, and textarea, and clicking on post comment, the Name,email, and website fields are deleted, and only the comment text get passed through,
as Anonymous, without email & website.

If I activate, from the dashboard, “Comment author must fill out name and e-mai”, and fill out the form, I get an error: ERROR: please fill the required fields (name, email)., from wp-comments-post.php, even though all fields have been completed.

The wierd thing is that, if a switch back to Twenty Eleven theme, comments work properly ??

Tried everything:
-reinstall/update wordpress
-deactivate/delete/reactivate plugins
-copy/paste comments.php and functions from Twenty Eleven theme
-used just comments_template() without comments.php

Any thoughts or ideas are much appreciated!

[No bumping, thank you.]