Hi JP 
CALL METHOD cl_batch_event=>raise(
EXPORTING
i_eventid = 'Z_MYEVENT'
i_eventparm = lv_param
Z_MYEVENT of course exists in SM64.
Not sure if that helps but the system has two application servers. On the other hand the two servers were there during the period when I would have said it worked just fine.
Cheers Otto