iPhone App doesn't get downloaded on iPhone 3G

I have creat开发者_StackOverflow中文版ed iPhone App supported with iOS 4.2 or later and tested on iPhone4.0 but it seems users are not able to downloaded my application on iPhone 3G. I couldn't find any settings specific to iPhone versions. What all I can see is the deployment target that is set to iOS 4.2. Could anyone please tell me what could be reason for my application not getting downloaded on iPhone 3G?

Thanks.

---

You should set your Base SDK to the newest version you have installed, and then set your Deployment SDK to the minimum FW you are planning on supporting, in your distribution/test/debug profile like this:

Base SDK: iPhone OS 4.2
Deployment SDK: iPhone OS 4.0

This way you get all the futures of your new base sdk and you set the minimum FW neded for your app to work. This should be set carefully, setting a Deployment too low may make your app go really crazy, eg. Base SDK: 4.3 and Deployment SDK: 3.0.

Hope it helps!