  Except for blocks with a cyclic or Klein four defect group, it is not known
in general whether the Morita equivalence class of a block algebra over a field
of prime characteristic determines that of the corresponding block algebra over
a p-adic ring. We prove this to be the case when the defect group is quaternion
of order 8 and the block algebra over an algebraically closed field k of
characteristic 2 is Morita equivalent to $k\tilde A_4$. The main ingredients
are Erdmann's classification of tame blocks and work of Cabanes and Picaronny
on perfect isometries between tame blocks.
