Dolphin 7.1, test version 16948.
When you attempt to create a new block (either New Item or New Block) by sliding the block into place, the block is not editable (remains greyed out).
If you then refresh the page, the block is removed to the inactive area and becomes editable. Once editable, you can move it back into position for use.
Using the latest Firefox browser on Windows 7 machine.
