Black bars appear above/below main content in full-screen mode
iTerm2 version: 3.0.0 OS version: 10.10.3 com.googlecode.iterm2.plist: com.googlecode.iterm2.plist No debug log because this is a visual issue; if one would be helpful I can provide one.
See the attached screenshot. When in full-screen mode (with "Native full screen windows" enabled) the terminal is letterboxed, with black bars appearing above and below the main content. Opening/closing tabs, showing the menu bar, closing/reopening iTerm2, and toggling between normal/fullscreen all have no effect. With "Native full screen windows" unchecked, the bars don't appear (but since OSX doesn't move non-native fullscreen to its own space, this isn't really a workaround for me).
In 2.x versions I would occasionally end up with this same appearance, but doing anything that changed the size of the window (showing the menu bar, for example) would fix it.