Pierre, u where right, a mismatch of res. My fault.
Anyway, ive tried in the same 25p project to deinterlace applying fieldskit to a nested seq (that has the original 25i footage plus univ count) and to that i apply twixtor (as i read in one thread here) and comes some really bad footage.
But if i first deinterlace in after fx and then apply twixtor to the rendered footage (now progressive)in the premiere timeline, i get some beautiful slo mo. Same settings in both plugins (2x duration in fielskit / input fields: none in twixtor). Im wrong again? I will send u the premiere project tomorrow (too late for me now)
Thanks for your quick and precise answer, Hernan