Drag and drop move fails with zip files. (XE 550)

[kwe]

Version used: FreeCommander XE 0.0.0.550)
Screenshot: http://imageshack.us/f/191/zipcopyfreecmdxe.jpg/
Note: Image can't show either the copy/move icon nor which keys I'm pressing so it may not be worth viewing.

To duplicate:
Create a folder. Call it 'folder1'
Put a few zip files in it.
Create a new folder in it. Call it 'folder2'.
Try to move the zip files into folder2 by dragging it.
The files remain in folder1 but have been copied to folder2.
Using shift to force move does nothing.

2nd test:
Drag the files around and drop them in same folder they are in (folder1).
This creates the result shown in image (duplicated files).

Non zip files appear to work better.

Best regards.