unfortunately apple did not design the magnet placement to support portrait-oriented ipad covers such as cradle-oriented keyboards.
as a result, the logitech ultrathin bluetooth case is mechanically unstable in portrait mode: the ipad simply tumbles backwards and crashes on to the table
(the fact that a premium product -$120- doesnt have keyboard backlighting -or even solar power for that matter- is also an egregious design flaw: but that's off-topic
hopefully apple will see fit to improve the distribution magnets in the ipad5!
(utilizing a better calibre of 'smart' magnets / electronics would also be appreciated: following the lead of the magsafe technology - tho in the converse- the magnets' inductive characteristics should dynamically adapt to the live load so that they increase their bond in peak moments to prevent unwanted sudden separation (eg tipping) while yet still retaining their low clasping threshold for slow deliberate detachments).
in the meantime: BEWARE!
apple's half-thought thru design leaves your ipad vulnerable in a cradle when used in portrait mode