2.02 added an uneditable Page Settings' "Class Key:" field [SOLVED]

just updated my site from 2.00 to 2.02, . I can’t edit any page any more. When saving I get the error:
[tt]Please correct the errors in your form before submitting.[/tt].
So I found on the ’Page Seettings’ tab that there’s a new(?) field named ’[tt]Class Key:[/tt]’ that request to be filled, was it there before? I don’t know.
Double-clicking on it pulls down three options:

• modxDocument
• modxResource
• class

Whathever I choose it seems that I can save the document, but it’s not actually saved when I come back: it’s all like before.
Any help? shold I just revert to 2.0?
Thank You

modx2.02, win7, xampp 1.7.3 Apache/2.2.14 (Win32) DAV/2 mod_ssl/2.2.14 OpenSSL/0.9.8l mod_autoindex_color PHP/5.3.1 mod_apreq2-20090110/2.7.1 mod_perl/2.0.4 Perl/v5.10.1 MySQL: 5.1.41 MySQL client: 5.1.41 Extensions PHP: mysqli - Firefox 3.6.10

Make *sure* you’ve cleared your browser cache.

Also, did you install the advanced or traditional package?

SOLVED
after rebooting both the server and the browser (it’s actually the same testing machine) this morning things are working as expected.
By the way it was traditional package
Thank you

I had the same problem, restarting only the browser did the job for me