A air carrier on approach to SPIM on the ILS to Runway 15 experienced two instances of localizer and glide slope disruption.

Narrative

ILS erroneous indication on approach. Descending out of 3;000 FT on approach to Runway 15 at SPIM with localizer and glideslope captured; flaps 5; gear up; speed 190 KTS; autopilot on. Inbound to DALNA; the aircraft pitched down and the airspeed started to increase. Autopilot was disconnected; airspeed within limits (220 KTS) for the flap five configuration. Approach was continued manually; glideslope and localizer indications returned to normal until just inbound from DALNA; at which point the glideslope pitched up and the localizer deviated to the right (climbing right turn indication). The current flight path was held manually; airplane was at flaps 20; gear down and airspeed 180 KTS. Once again; the glideslope and localizer indications returned to normal and we broke out of the weather at 1;200 FT; however; this delayed final configuration flaps 25 (1;100 FT) and shortly thereafter flaps 30 were selected at 800 FT. Stabilized and visual at 500 FT; approach continued to an uneventful landing.