How to reproduce infrequent 404?

Question

I have an application in the Windows Phone Marketplace that sends server data (Tomcat, Java, Spring) through a POST call. If an error occurs in the application, the email developer has added an option. I got error messages from some users (20/300) and it shows that the http client returns 404 against the POST request. I don’t know why some users get 404 while they are working on users’s vacation. If I turn off my test mobile Wi-Fi and cellular and launch the application, then I can reproduce the same problem that users face. But when I ask them about their Internet connection, they declare their work.

My question is: how can I try to debug and reproduce this problem? Any pointers ..?

Answer 1

@Chase Florell pointed in the right direction. When users changed the network, the application worked fine.