Why do table variables work when I execute this query in SQL Server Studio but not via odbc_exec?

Question

The query in the PHP code below works fine when I run it via Microsoft SQL Server Management Studio, but gives

Warning: odbc_fetch_into() [function.odbc-fetch-into]: No tuples available at this result index

at the odbc_fetch_into call (and does not have any rows).

$sql = "DECLARE @ValueList TABLE (CheckValue int)
 INSERT INTO @ValueList VALUES (1)
 INSERT INTO @ValueList VALUES (2)
 INSERT INTO @ValueList VALUES (3)

 SELECT VL.CheckValue
 FROM @ValueList AS VL";

$rs = odbc_exec($conn, $sql);

$badValues = array();

while (odbc_fetch_into($rs, $missRow) !== false) {
 $badValues[] = $missRow[0];
}

Other queries against the database that don't use table variables work fine in this context. And calling odbc_errormsg afterwards doesn't return an error.

PHP Version 5.2.6, SQL Server 2005