paypal not returning to url specified in settings
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    <form action="https://www.paypal.com/cgi-bin/webscr" method="post" accept-charset="utf-8">  
    <input type="hidden" name="cmd" value="_xclick" /> 
    <input type="hidden" name="charset" value="utf-8" /> 
    <input type="hidden" name="business" value="address@gmail.com" /> 
    <input type="hidden" name="item_name" value="company - product" />
    <input type="hidden" name="item_number" value="1" />
    <input type="hidden" name="amount" value="0.01" />
    <input type="hidden" name="currency_code" value="GBP" />
    <input type="hidden" name="return" value="http://mywebsite.com/folder/success.php" /> 
    <input type="hidden" name="cancel_return" value="http://mywebsite.com/folder//booking.html" />
    <input type="hidden" name="bn" value="company_BuyNow_product_UK" /> 
    <input type="image" src="https://www.paypal.com/en_US/i/btn/btn_buynowCC_LG.gif" name="submit" alt="Buy Now" /> 
    </form>

I've set Website Payment Preferences > Auto Return for Website Payments > radio button to 'on'.
I've also set the redirect url to match my button code:

    <input type="hidden" name="return" value="http://mywebsite.com/folder/success.php" />

When the button is clicked, the browser redirects to paypal, shows my product details correctly and allows me to pay, then it says 'Review your information' while the loading wheel spins for around fifteen seconds, a payment received conformation email comes to me, then nothing happens, the wheel keeps spinning over and over indefinatly stuck on the 'Review your information' screen never redirecting to my return url...

Not found anything related on google or here or paypal docs.