Problem on DB connection

My Webserver has a serius problem on DB connection via PHP. Would you show me any advice or instruction? ^^; My system is configured as follows: OS : Solaris 2.8 WebServer : iplanet 6.0 SP5 DB Server : Oracle 8.1.7 .. and PHP4.1.2 (installed as DSO) The WebServer starts and works normally. But some times, it tells me an error message via my browser ---------------------------------------------------------------------------- ------ Warning: Failed opening '/cont01/sgt1/web/docs/test/oci_db.php' for inclusion (include_path='.:/usr/local/lib/php') in Unknown on line 0 ---------------------------------------------------------------------------- ------ Once the problem occurs, no php file works any more until restarting webserver (it always shows me same error mesg.) After restarting webserver, it works normally for 5~10 minutes and same problem occurs again!! (cf: DB connection via 'jsp' has no problem) For your information.... 1. Some 'WARNING' had been thrown on installing PHP at first time. (it happend on 'make' step, but installed seccessfully, anyway. -_-;;) I guess this warning message may be concerned with my problem. ---------------------------------------------------------------------------- ------------------------------------ oracle.c: In function `zm_startup_oracle': oracle.c:328: warning: passing arg 1 of `zend_register_list_destructors_ex' from incompatible pointer type oracle.c:329: warning: passing arg 2 of `zend_register_list_destructors_ex' from incompatible pointer type nsapi.c: In function `nsapi_request_dtor': nsapi.c:438: warning: passing arg 1 of `nsapi_free' discards qualifiers from pointer target type nsapi.c:440: warning: passing arg 1 of `nsapi_free' discards qualifiers from pointer target type ---------------------------------------------------------------------------- ------------------------------------ 2. I've already uninstalled and installed again all system(including OS) several times. But, the situation does not improved yet. **************************************************************************** *************************************** Would you give me any advice or instruction? ^^; Any reference or similar case will be very helpful.