When
two objects are dissolved on one track, you need to drag one of them
into another track. If no track is available, add one by right-clicking
a track head, selecting Insert track
followed by the appropriate
track type.
In the toolbar, enable
tool 
Vertical
dragging, which can also be achieved by pressing the V key. Grab the corresponding object
at its info line and drag into a second track of the same type, i.e.
pictures into a second picture track, etc. You may have to add a track.
Fade-ins and outs
are now no longer linked up with each other and can be edited freely...
Show
example.