SQL & PL/SQL

I have a table that has about 900K rows. It has a primary key on an integer column.

It is taking 18 seconds to delete a single record using the primary key. Using an SQL statement like: delete from tblItems where ID = 32444;

Here is the execution plan:
Looks normal.

Operation          Options     Object           Rows    Time   Cost   Bytes    Access Predicates 
DELETE STATEMENT                                  1       1       3      22     
DELETE                         TBLITEMS             
INDEX              UNIQUE SCAN PK_TBLPRODUCTS     1       1       2      22    "INTITEMID" = 919364 

Here is what I have tried to resolve the issue. Rebuild primary key index and then analyze the table.

Nothing has improved the speed. I have run out of ideas.
Does anybody else know what I should try next.

Thanks,

Chris