They shouldn't be there. The previous version used them, but they are no longer needed. The problem is that DW is looking for them, not that they aren't there.
Usually refreshing the layout will fix the problem, since DW is looking for them based on that window being open when DW was closed. While it was closed you updated Site Import, which deleted the floater since it has been replaced. Now we just need to tell DW to stop looking for it... Looking through this forum it appears a good handful of people have run into the problem.
The good news is it can be ignored and shouldn't effect functionality. But it is annoying. Maybe try changing your workspace layout setting to another mode like "designer" or "developer" and then close DW and clear the filecache.dat file before opening it again.
The problem is that DW has in its memory that that window was open in your layout and wants to return your view to what you had before, but that window has been replaced by one with a different name in the new version you installed.
You could always install the old version, open DW, then make sure to close the progress window before closing DW and installing the newer version, but that really shouldn't be necessary.
