So any one has any clue wat I should see to check this.

Can't tell much without sample code. Also, you didn't describe your environment, how your servers (live and dev) are setup. Are they in the same host? If so, are the two host having identical environment? You may also want to show the sample code that do the posting to both servers. Also, "post a request to the live server" and "post an xml to the dev server" seem to be similiar yet distinct. In short, your problem description is vague. See, your title doesn't have anything at all to do with your question. May I suggest you to read How do I post a question effectively??