Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to report
a bug at http://bugs.php.net/how-to-report.php

See:
http://docs.php.net/manual/en/pdostatement.columncount.php

No result set == no query executed.
(like prepare() not followed by execute())

Well, are you can see from the fetchHost() function, I call prepare() 
then call execute().

This is the actual function that I use:

function fetchHost($hwAddr)
{
	global
		$appErr,
		$sqlPDO;

	$sqlQuery = "SELECT * FROM hosts WHERE hw = ?";

	var_dump($hwAddr);

	if (($sqlStatement = $sqlPDO->prepare($sqlQuery)) === false) {
		$appErr = $sqlPDO->errorInfo();
		return (bool) false;
	}

	var_dump($sqlStatement);

	if ($sqlStatement->execute(array($hwAddr)) === false) {
		$appErr = $sqlStatement->errorInfo();
		return (bool) false;
	}

	var_dump($sqlStatement);

	var_dump($sqlStatement->columnCount());

	if ($sqlStatement->columnCount() < 1)
		return (bool) true;

	return $sqlStatement->fetch(PDO::FETCH_ASSOC);
}

The results of the var_dump()'s are:

string(17) "00:e0:4c:20:dc:20"

object(PDOStatement)#3 (1) {
  ["queryString"]=>
  string(32) "SELECT * FROM hosts WHERE hw = ?"
}

object(PDOStatement)#3 (1) {
  ["queryString"]=>
  string(32) "SELECT * FROM hosts WHERE hw = ?"
}

int(3)



I certainly don't have 3 entries returned since there are ONLY two 
inserted into the database :) and 00:e0:4c:20:dc:20 really doesn't 
match any the them.

But the query was executed. This is the requirement to you can get the number of fields.

I am sorry, i've confused rowCount() with columnCount(). The bug is 
bogus. However, I am not sure what to use in order to see how many rows 
have been returned by the select command. rowCount() is to be used for 
INSERT, UPDATE and DELETE only.

Is there any way to get the rows returned by SELECT other than 
count(fetchAll()) ?