Menu doesn't work with ajaxify regions

I use context 6.x-2.0-rc2 and menu-block 6.x-2.3 to show in a block the menu tree of a particolar sub-section of primary-links.
In the block are visible the current menu voice, all the voices of the same level and eventually the sub-voices of the current node.

If i use ajaxify regions for this block, i can't se the sub-voices, otherwise all works fine.