I've set up Fundraising and and double checked that my IPN settings are correct. I've tested a couple of transactions and they are going through, in fact they show up in the IPN history with an HTTP response code of 404 and it says it is retrying. Currently it's retried 7 times so it seems that it won't be going through.
I double checked with Dreamhost and they say they are not blocking IPNs, so I'm a little lost now. Here's my page: http://www.redpegasusgamesandcomics.com/fundraisers/the-big-move/