Programming :: Error 97 = Address Family Not Supported By Protocol?

I have a very strange problem in a C++ RHEL4 app. Here is the code: socket(PF_INET, SOCK_STREAM, 0) returns errno 97 socket(PF_INET, SOCK_DGRAM, 0) returns successow that is strange or what?additional info:1. Extracting the above code into a test program, both return success.2. Placing the above code into the 1st line of my app, error as above.3. I ran app and test program in the same terminal window.4. My app links in many static libraries 5. My app runs fine when compiled and linked on RHEL56. My APP is a ss7 endpoint (SIP <==> SS7 message flow)7. I verified PF_INET, SOCK_STREAM, SOCK_SGRAM values are correct.