copy-paste issue in Keynote 6.6.2

hi!

somehow it is impossible to copy and paste objects (shapes, text, pictures etc.) in Keynote from one slide to another or within the existing slide. using both keyboard shortcuts and menu functions yield no result. the copied objects just do not appear. any ideas why is this happening?

when i choose Cut it partially works - the object disappears, however it is not possible to bring it back using Paste.

thanks in advance.

janisjanis