Php 4, linux & err 3106

I need to manage an intranet web server with dynamic pages accessing an Oracle 8.1.6 DB running on Win NT. My web server is on Linux Slackware 7.1. I have installed the client libraries on the linux box, can connect without problems to the Oracle server thru sqlplus, and run queries. My problem comes when I try to run the same queries from a php page. I can connect (I receive a valid response if I send a OCIServerVersion command), but when I run the same query I had run in sqlplus I receive an error:

ORA-03106 fatal two-task communication

I have the TWO_TASK environment variable set to /OraHome1/network/admin (where my tnsnames.ora file resides)

I don't have any more ideas, please help. Is it a bug? a misconfiguration on my linux box?

Thanks in advance!

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