Actually I found the code and fixed it and now all transactions that were failing are now working, for anyone else on old code like me here is the fix:
edit includes/modules/payment/paypal.php
inside the function "formFields"
add a line after:
$item_number = '';
for ($i=0; $i<sizeof($order->products); $i++) $item_number .= ' '.$order->products[$i]['name'].' ,';
$item_number = substr_replace($item_number,'',-2);
This is the new line to add after:
if( strlen($item_number) > 127 ) { $item_number = substr($item_number, 0, 124) . "..."; }
That fixes the problem.
Hope this helps someone.
Mike