Postgres.exe Process taking too much memory and CPU usage - making the system extremely slow.

Hi All.

I have a program which import some 6000-10000 records in Postgres
database. However the import of data is successful but the postgres.exe
almost takes up entire memory and CPU.

I could see in the process list there are lot of postgres.exe are
running and one of the postgres.exe has taken up 98% of CPU.Even
stopping the Postgres database service is not killing this processes
running so I have to kill them individual processes.

I have the below parameters set in Postgresql.conf file.

# - Memory -

shared_buffers = 512MB

work_mem = 256MB

# - Free Space Map -

max_fsm_pages = 500000

max_fsm_relations = 5000

Below is the autovacuum settings

autovacuum = on

log_autovacuum_min_duration = 0
.

autovacuum_max_workers = 20

autovacuum_naptime = 5min

autovacuum_vacuum_threshold = 50

autovacuum_analyze_threshold = 50

autovacuum_vacuum_scale_factor = 0.2

autovacuum_analyze_scale_factor = 0.1

autovacuum_freeze_max_age = 200000000

autovacuum_vacuum_cost_delay = 20

I am using Postgres 8.3.5 on windows XP environment 32-bit.

I would really appreciate any help on this as this is one of the show
stopper for us.