Slow Locally On Supersized Server

i have a nightly import ( about 20 tables ) and it takes up to 5 hours..we have one table of about 800,000 lines and the rest are between 1000 and 200,000 this is very slow when i monitor the import i see a very long amount of wait for the SQLnet from client ,

i run the import on the Database server itself .. if i check the current statement i see it's moving from one to one for instance i have

SELECT /*+ all_rows ordered */
"A".ROWID, 'REPORT', 'CONTRACT_LVL', 'SYS_C001329497'
FROM "REPORT"."CONTRACT_LVL" "A"
WHERE NOT (LENGTH (bonus_nat) <= 31)
then
SELECT /*+ all_rows ordered */
"A".ROWID, 'REPORT', 'CONTRACT_LVL', 'SYS_C001684584'
FROM "REPORT"."CONTRACT_LVL" "A"
WHERE NOT (LENGTH (outcome_cd) <= 1)

etc and it takes hours DB is on windows 2003 runnin oracle RDBMS 9.2.0.7 while the import screen show 185000 lines imported..I also see a lot of consistent gets for this sessions raising at that time..Would it be better to export import without statistics ?

I need also to mention that the dump file comes from a linux hosted Database don't think it will make the difference for a exp/imp.It's a peoplesoft Database there are a lot of tables more than 15000 and if i take the table mentioned above and i want to check its constraints it takes decade before toad can display them.I have seen that we have a incredible amount of constraints on those tables it might be the reason .

I just wonder if the system catalog needs to be tuned ? /* Update */ why but now the huge number of wait is no as "Library cache lock".