iPhone + DevToolsCore.framework error

I am using following environment:

1. MAC OS 10.5.7
2. iPhone SDK 3.0
3. Xcode 3.1.3

And my client is using:

1. M开发者_Go百科AC OS - Snow Leopard.
2. iPhone SDK 3.1
3. Xcode 3.2

Whenever my client runs the application that I have developed on my Machine he get errors of DevToolsCore.framework (which I am not using in my application).

Can anyone help me in this.

Regards, Pratik