  We analyse the width of the $\theta(\frac12^+)$ pentaquark assuming that it
is a bound state of two extended spin-zero $ud$-diquarks and the $\bar s$
antiquark (the Jaffe-Wilczek scenario). The width obtained when the size
parameters of the pentaquark wave function are taken to be close to the
parameters of the nucleon is found to be $\simeq 150$ MeV, i.e. it has a normal
value for a $P$-wave hadron decay with the corresponding energy
release.However, we found a strong dynamical suppression of the decay width if
the pentaquark has an asymmetric "peanut" structure with the strange antiquark
in the center and the two diquarks rotating around. In this case a decay width
of $\simeq$ 1 MeV is a natural possibility.
