oracle instantclient 10 problem

Ehlo, I compiled php-5.2.3 with the "--with-oci8=instantclient,/opt/instantclient_10_2/" switch and it completed with no errors. First it seems to work well, but now, sometimes i get the infamous - OCIEnvNlsCreate() failed check LD_LIBRARY_PATH - error. The funny thing is, those variables are all set. I dont have really a clue why this appears now. versions in use apache 2.2.4 php 5.2.3 instantclient 10.2.0.3 These parameters are set before the apache is started ORACLE_BASE=/opt/instantclient_10_2 ORACLE_HOME=$ORACLE_BASE NLS_LANG=GERMAN_GERMANY.WE8ISO8859P9 PATH=$PATH:$ORACLE_BASE LD_LIBRARY_PATH=$ORACLE_BASE TNS_ADMIN=/etc ORACLE_SID=SID Any suggestions would be much appreciated. TIA Rainhard