Right click on highlighted text in a table in Firefox unselects it

Hi, when I highlight(select) some text with the mouse in a table and try to copy it to the clipboard thru the browsers context menu, the right click causes unselection of the text and the default context menu with the navigation buttons on the toop opens (not the one, which allows the copy/paste). This hapens only in tables in Firefox, Chrome works fine. Is there a way to “hack” this bug?

thanks