show some example of your code.
a lot of times you need to make sure you are using quotes in your form, .. otherwise it will only pickup the first word.
<?
echo "<form method=\"POST\" action=\"" . $_SERVER['PHP_SELF'] . "\">
<input type=\"hidden\" name=\"var\" value=\"a few words here\">
</form>";
?>
only 'a' would show up if 'a few words here' was not in quotes.
it's really hard to say without seeing your code.