How to install universal application in 2G iPhone

i have created an universal application using xcode 3.2.4. in my build setting i have set "target device" as 3.1.2. This application is working fine with iPhone 3G, iPhone 4 and iPod touch 3G. But i am facing "Unsigned" error if i try开发者_运维技巧 to install my universal application into my 2G iPhone which have iOS 3.1.3 I have included 2G iPhone UID into provisioning file. But still getting same error. please guide me as how to over come this issue and make my universal app to work in 2G devices also.

thanks in advance. Ram

Unsigned seems to imply you still have an issue with your provisioning profile. Open the Organizer in XCode, click on the device on the left, and look at the provisioning profiles that are associated with it to verify that the one to which you assigned that device's UID is actually on the device.