Copy to clipboard from Gmail

I have observed a strange(may be not strange) thing when copying HTML content from gmail.
It does not immediately copy, but seems to be stuck for around 3-7 seconds after which your copy is successful. Try copying something from gmail(any HTML) and immediately paste it to a notepad, it would not paste anything or would paste what was previously available in the clipboard. In the meantime, the browser is nonfunctional.