it cant be the starter motor if the engine turns over.
if the code light remains lit on the dash when it does not start then the problme is the aerial around the ignition switch. a wiggle of its connector should sort it.
a common cold starting problem on the 1.2 is a loss of compresson from a head gasket leak. on the 1.2 a head gasket leak can go unnoticed, not using any oil or coolant or even causing a noticable misfire, yet the low compression makes cold starting difficult. if you only have problme starting the engie when it is cold then a compression test is needed.
a common warm starting problem on the 1.2 is the crank sensor. if you only have problmems starting the engine when it is warm (been used recently) then the crank sensor should be top of your list.
if the starter motor turns more slowly than you would expect then a poor battery is most likely, although dirty battery contracts and a rotten earth strap (from gearbox to chassis) are also possibilites.
