Oracle Database Discussions

Dear colegues,
I'm running Oracle 10.2.0.4 on RHEL5

Application executes always same query using bind variable.

I do several calls in a row of this application and see that number of loads / invalidations of this SQL when querying v$sqlarea view are quite strange (please note that no stats capturing / change of table structure is done between calls, so I do not see the point in invalidation of SQL):

SQL> select sql_id from v$sql where sql_text like 'select pm.ri  from gui g ,gui_methods gm%';

SQL_ID
-------------
7hkj2qyu2tuas  

Call1 and then query in DB:

SQL> select last_active_time , LAST_LOAD_TIME, FIRST_LOAD_TIME, LOADS, INVALIDATIONS from v$sqlarea
  2  where sql_id='7hkj2qyu2tuas';

LAST_ACTIVE_TIME     LAST_LOAD_TIME       FIRST_LOAD_TIME          LOADS INVALIDATIONS
-------------------- -------------------- ------------------- ---------- -------------
29-May-2013 02:40:57 29-May-2013 02:40:57 2013-05-28/04:25:20         39             9

Call2 and then query in DB:

SQL> select last_active_time , LAST_LOAD_TIME, FIRST_LOAD_TIME, LOADS, INVALIDATIONS from v$sqlarea
  2  where sql_id='7hkj2qyu2tuas';

LAST_ACTIVE_TIME     LAST_LOAD_TIME       FIRST_LOAD_TIME          LOADS INVALIDATIONS
-------------------- -------------------- ------------------- ---------- -------------
29-May-2013 02:41:07 29-May-2013 02:41:07 2013-05-28/04:25:20         10             0

Call3 and then query in DB:

SQL> select last_active_time , LAST_LOAD_TIME, FIRST_LOAD_TIME, LOADS, INVALIDATIONS from v$sqlarea
  2  where sql_id='7hkj2qyu2tuas';

LAST_ACTIVE_TIME     LAST_LOAD_TIME       FIRST_LOAD_TIME          LOADS INVALIDATIONS
-------------------- -------------------- ------------------- ---------- -------------
29-May-2013 02:41:22 29-May-2013 02:41:22 2013-05-28/04:25:20         41            10

Can you please share your ideas why SQL stats is changing this strange way.
Thanks in advance for your time.