TOPIC: Blank Screen with Try Again button

After hitting "Process Donation" on the information confirmation page, I am redirected to a blank page with a try again button. I have upgraded and it still has not fixed my problem. I checked other posts and saw that rekeying Authorize.net should fix the problem. I just rekeyed it on January 3rd. Has anyone found another solution?
Page looks like this:

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(Try Again)

Hi - Have you received a response to this?

We had a client that has 1000 authorize.net authorize charges that appear to be related to this "Try Again" - you can literally sit their and keep pressing enter (and getting the try again) - BUT - this is doing an authorization with Authorize.net.

We are using an older version - so this may be a known issue - but it is a major security issue - so please let me know if you have resolved this and how. You will have to void the transaction in Authorize.net and the kicker is that it does not write a valid record to DT Donate - so you don't even see donation entered - in our case we were obviously being hit by a bot or hackers (and the authorize.net notifications were not passed back to us - so we missed the problem completely).

Cheers,

Peter Beare - Bear Web Design