What I meant is, the function call was just like you said when I first noticed the problem above:
CALLFUNCTION'Z_SAVE_PARTIAL'
INUPDATE TASK
EXPORTING
iw_tegrk_parc = w_tegrk_parc
it_tegrp_parc = t_tegrp_parc.
I just got lazy and didn't revert it after the change to TABLES 