I'm am not sure if this is only odbc related. It might be only the function where this problem turned up for me...

Example of odbc_fetch_into call that stopped working from 4.0.6:

43
44  while (@odbc_fetch_into($query_id, 0, $result_array)) {
45     list($var1, $var2) = $result_array;
46     ...
47  }
48

Running this script results in an error:
Fatal error: Only variables can be passed by reference in D:\Inetpub\wwwroot\bb\location.php on line 44

Fortunately some of my scripts call odbc_fetch_into a little different:
Example of odbc call that still works in 4.0.6:

09
10  function db_fetch_into($id, $number) {
11  	@odbc_fetch_into($id, $number, $result_array);
12  	return $result_array;
13  }
14
15  while (list($var1, $var2) = db_fetch_into($query_id, 0)) {
16    ...
17  }
18

PHP.INI:
allow_call_time_pass_reference = Off