Display problem

I bet you can solve it by clearing the cache.

This would indicate that something in your system is preventing the .css files from loading. Perhaps they were installed incorrectly or perhaps your theme is somehow nuking them.

Just a wild guess, do you use internet explorer? Internet explorer until i think 9 can't load more then 31 css files, so maybe the views css file isn't loaded. To fix this you can turn an aggregation of css in the performance settings of drupal.

Additional you should switch to a standard-conform browser :)

I have the same problem in installation where views was updated. On a new installation there is not problem.
The problem comes with the file views-admin.theme.css . When I move the file into my admin theme, but with the same name, the problem still exist, but when I rename the file to views-admin-theme.css and include it to my admin theme, the problem fixed.
I don't give this example like a fixing for the problem, I just give more information to the developers of the module for the problem.

Wich themes are you using? Please try with a core theme to see if you still has the problem.

Experimenting a little:
I see in the pdf, that the maintenance mode is activated, i also tested with JS and CSS agregation and everything OK, mm this seems really like a (theme) cache problem.

I make tests with all core themes, with aggregation and without. The result was the same. I disable all extra modules that was installed, but the result again was the same.
Before updating the Views all was OK, for this reason I think that is not a cache problem.
Just after the updating the system cut the file "views-admin.theme.css" from the list of sylesheets files. It seems like not recognize the file like .css .

Well, going a little deeper i see that the code in views_ui_get_admin_css() has changed since RC1, however, both views-admin.css and views-admin.theme.css are 'statically' added to the array, that is to say they don't depend on any condition to be added, so we need more info here:
@milenv
Wich specific theme are you using?
Could you attach some pictures on how it looks (if it's the same as the pdf no need to)?
In the mean time you could check that those files (views-admin.css, views-admin.theme.css and depending on the theme views-admin.$theme_key.css e.g. views-admin.seven.css) really exist in the right directory: your-drupal/sites/all/modules/views/css/

Sorry for my late answer. In my previously post I wrote that I has tested with all core themes as admin theme, and the result was the same.I use for admin theme "Seven" theme . The files views-admin.css, views-admin.theme.css exist.
The system work perfectly intil I update the Views module to the last version.

@milenv Thanks for updating the issue. Is this still a problem in the latest stable version of Views?