I've posted this in some of the hybrid threads, but I thought it might help to give it a dedicated thread.
The problem is that the Firethorn mobile banking application will not work with 428 or any of the hybrids. I get an error stating "Certificate not issued from expected source. The application is currently in offline mode." As I posted in another thread, I found a site where someone with a similar problem was told by their bank "the problem you are experiencing with the mobile banking application is a result of the beta firmware (release) on your device. The update contains out-dated versions of the root certificates for your device and mobile banking relies on the root certificates to run securely. Since the application is unable to find the proper root certificates, it will fail.
I have used the same method to install each. To begin with, I used BBSAK to wipe the phone to eliminate any issues. I then install the device software. Then I install my firethorn mobile banking application.As I said, the official 320 works, but the leaked 428 and all hybrids I've tried fail. One last thing, the Verisign/RSA Secure Server Root certificate shows a red x and says it expired January 7, 2010. At breiti's suggestion, I tried sending it to myself and reaccepting it and that did not work. I also set the device date back before that date and it changed the x to a yellow ?, but the problem remained. This has been true of the 428 and all hybrids.