INPUT CLASS destroys global get?

[eluser]judico[/eluser]
xwero

for a get request something like http://www.example.com/sample?txt=foo&cat=bar
the sample in cited in #7

Code:

parse_str($_SERVER['QUERY_STRING'],$_GET); #from response #7
print_r($_GET);

yields

Array ( [/sample] => )

whereas something like this

Code:

$keys = explode('?', $_SERVER['REQUEST_URI']);
if(count($keys) == 2){
    print_r(explode('&', $keys[1]));
}

yields

Array ( [0] => txt=foo [1] => cat=bar )

is there something environmental like a config setting that makes your snippet yield something similar?
what's the best practice here for this type of situation?
thanks