Hello Alexandru Paul Papuc,
There is not a demo of a skinned selectbox with items overflow because this is not a core feature of the control, however you can easily create one by:
1. Add a selectbox with many items.
2. Put the CSS I gave you a couple of days ago in the <head /> section of your page.
But again - I was not able to reproduce the issue you are experiencing. When I mentioned global styles, I did not have in mind any <select /> rules, because such would not affect the skinned selectboxes, because they do not have anything in common with the real selectboxes - they are just a <a /> tag next to the <select />. The issue you are facing may be caused by relatively or absolutely positioned parents, etc. Try to exclude your own stylesheets and check if the problem persists. I tested it with different versions, and I cannot reproduce the problem.
For your convenience I am sending you a sample page with overflown selectbox items.
the Telerik team