Unable to recover from components on top of each other

[baggepinnen]

I managed to click "align horizontally", after which two components ended up on top of each other. This led to a NotUnique exception when I tried to remove the one on top. I had to redefine the filtersingle function to return the first found component in order to be able to recover the situation. If two components are on top of each other, I guess it would make more sense to select the top one rather than error?