Nate's got it.
The original linked website specifies that they require at least Acrobat/Reader 8.2, and doesn't mention any other plugins. That means that most likely they are using Adobe Live Cycle Policy Server on the backend (Business DRM solution), instead of Adobe Content Server (Consumer DRM solution). Adobe Reader does not support Adobe Content Server documents, and Adobe Digital Editions, or any of the RMSDK based apps, such as Bluefire Reader, don't support Adobe LC Policy Server documents.
I don't remember Adobe releasing a Acrobat/Reader app for the iPad, but there is an Android one (however it was based on RMSDK, so I don't think it ending up supporting Policy Server documents either). So I don't think you will be able to read the document as is, on your iPad. Sorry.
UPDATE:
Adobe released an iOS version of Reader today, and the description says it supports 'Adobe LiveCycle rights-managed PDF files'
http://itunes.apple.com/us/app/adobe...469337564?mt=8