hp 4700 AirPrint

HP have an ePrint app that supports the 'HP Photosmart C4700 All-in-One Printer Series' printer (from this page) - you could try that. Otherwise there are third-party printer apps such as Print Central For iPad and Print n Share which might work with it

I had the same problem and followed your advice. I can now print things like photos but not e-mails. Do you know if this is a limitation of the app or am I doing something wrong?