funding v 2.2.4 and ipn connect question for simple payments

Hi,

Using version 2.2.4 of fundraising with simple donations. Problem is that the IPN does not seem to be working. I have tried with the paypal sandbox and a few different live accounts and they donations are never saved in the back end and the thank you emails never go out. This is on a fresh wp 3.5 install. I had Bullet proof security installed, but have deleted the htaccess file it creates and the plugin itself, but no change in behavior. I continually get the "Oh No, we can't find your Pledge. Sometimes it take a few moments for your Pledge to be logged. You can try refreshing this page" message

any ideas?

thanks!