create vector layer. Create 2 shapes select 2 shapes ,then in tool options select 'group' then move that group there will be a visual bug till you ungroup the shapes
Ack.
*** Bug 342925 has been marked as a duplicate of this bug. ***
*** Bug 347657 has been marked as a duplicate of this bug. ***
This issue happens on Linux, but I can also confirm that it happens on OSX as well. Seems to be a canvas refresh problem.
This has actually always been broken. I checked back as far as 2.5...
This works fine in the SVG branch!