Paypal Return URL

I need to allow recurring subscription to take place. So far, It is looking good except that Paypal is not honoring completely the "return" hidden variable value. It does the redirect but it omits the supplied query string. It does add couple querystring variables such as www.mysite.com?auth=XXXX&form_charset=YYYY

For my solution, I want to rely on some values on the query string if that possible. Otherwise, I would have to store that temporary info in Session.

Any ideas?

    <form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post">

        <input type="hidden" name="cmd" value="_xclick-subscriptions">
        <input type="hidden" name="business" value="MerchantEmailAddress" />

        <input type="hidden" name="item_name" value="Description of Transaction">

        <input type="hidden" name="a3" value="5.00">
        <input type="hidden" name="p3" value="1">


        <input type="hidden" name="t3" value="M"> 
        <input type="hidden" name="src" value="1">

        <input type="hidden" name="custom" value="111.111111" />
        <input type="hidden" name="invoice" value="11" />

        <input type="hidden" name="cancel_return" value="http://www.MySite.com/?Cmd=Cancel"   />
        <input type="hidden" name="return" value="http://www.MySite.com/?Cmd=Return"   />
        <input name="notify_url" value="http://www.MySite.com/?Cmd=Notify" type="hidden">

        <!-- Display the payment button. -->
        <input type="image" name="submit" border="0" src="https://www.paypalobjects.com/en_US/i/btn/btn_subscribe_LG.gif"
                alt="PayPal - The safer, easier way to pay online">
        <img alt="" border="0" width="1" height="1"
            src="https://www.paypalobjects.com/en_US/i/scr/pixel.gif">
    </form>

Adding the rm=2 variable and value should work. That would tell PayPal to send information back as a POST. If you have Payment Data Transfer enabled in your seller account it would overwrite the rm value and the information returned to your site from PayPal would always be a GET.