Regarding the test file you made in the above post, strings in single quotes do not get parsed, strings in double quotes do however
So
Code:
$moo = 'baa';
echo '$moo<br />' . "$moo";
will result in
Anyway, are you by ANY chance doing this query INSIDE a function() declaration?
If so, make sure you add "global $vboptions;"
If not, add "var_dump($vboptions);" in front of the query and see what the output is.