in 2.0, when browsing files of a project, if you click a filename it is previewed in the content pane. when double clicks, it opens and it's added to the top o the sidebar. good.
in 3.0 it happens the same BUT the filename is added to the top of the sidebar at the first click (on previews).
with the terrible effect that if you double click a file to open it, you always end up opening the file above it ! (the first click insert the file name at the top, the list goes down, the second click opens the other file)
the only solution is to activate "View->Side Bar->Hide Open Files" ... but why?