Running Apache 1.3.12 with recently dl'd 4.0RC1 and 
the InterBase 6.0 Linux install...

  The following :

<pre>
  $db = ibase_connect($host,$user,$password);
  $sql = "SELECT * FROM Test";

  $result = ibase_query($db,$sql);

  $row = ibase_fetch_row($result);
  print "ID : " . $row["test_id"] . " : " . $row["test_string"];

</pre>

  Produces absolutely nothing except the text I embedded. I saw a function 'ibase_errmsg()' in the source code but it doesn't do anything when I call it, I assume it's defined but currently does nothing.
  When I changed the array references to 0 and 1, I get this in a popup window (IE 5.0) :
  
  Internet Explorer cannot open the Internet site http://xxx.xxxxxxx.xx.xxx/test.php.  The server returned and invalid or unrecognized response.

  I configured PHP like this '--with-apache=../apache_1.3.12 --with-ibase'.  My IB install is in /usr/local/interbase with /usr/interbase a symbolic link pointing to it.  It seemed to compile fine, but for some reason it included MySQL and GD support, neither of which I actually want.  I'm not sure that is related to this anyway.