I still don't see what the problem is - your syntax is correct. This:
Should work without any troubles. What I can tell you is that the word 'password' will need to be referenced as a string - password is reserved in SQL. Thats why I tend to write all my queries with backticks and strings where required:
$sQry = sprintf("SELECT * FROM Table WHERE username='%s'", mysql_real_escape_string($username));
$rQry = mysql_query($sQry);
SELECT * FROM `myTable` WHERE `myField` = 'MyVal'
For example. Other common ones that will trap people are 'number' and 'date'. This is probably why some of your numbered examples did not work, it is attempting to run the actual password function instead of identifying the password column.
Try turning on your error reporting, very first line in your php:
This will tell you if you have any syntactical or logic errors that could hinder the program execution. Try that, see if it gives you any errors.