'Press up or down to cycle blocks' bug

[cromignon]

If there's more than one block to press 'Enter' to make disappear, I'm given the option to cycle through them using Up or Down. Repeatedly pressing Up contiously cycles 'from right to left', and wraps around. However, pressing Down cycles 'from left to right', but STOPS at the last block on the right, meaning it doesn't wrap back around to the left-most block.