I apologize if this has been mentioned -- I can't find any way to search the forums.  (No magifying glass, search bar etc.)

If a storage chest, for example, has the max number of items, including one stack of ice, if you try to add ice from your inventory, it will not add to the chest.  If you remove 1 item so that there's a space in the chest, the ice will stack, and then you can re-add the item you displaced.  (Happens with all items; ice was just an example).

Confirmed in 0.39, I was about to report it too :)

Thanks for the bug reports!  Will work to get this fixed in the next version.

yep, it still happens

This should now be fixed in v0.40!  

Will probably try to make it so that you can transfer either 1 item, or the whole stack by holding Shift in the next version, since there's probably times when you don't want to bring the full stack with you.