Recently I noticed all the new windows are popping up in the top left. This is annoying because the top bar blocks the title bar of the new window. See screenshot of Tunesviewer with Firefox, Tunesviewer can't be moved without alt-drag trick.
Yeah by-default Ubuntu opens it in the top-left corner of the desktop. You can open it in the centre by doing the following:
Ideally, the window manager in Ubuntu should restore the last known position of an application window, but it does not do that unless an application remembers its own window position. (See reported bugs)