Oh man. That is not good news. It has been notorious on the DNA as an ongoing problem, regardless of a new sim or reseating/cleaning. For your sake, I hope it is an isolated incident. If you can, wait to reseat it before going to sprint and having the issue documented.
Sent from my HTC6435LVW using Android Central Forums
Any paper clip will work fine. popping it out is easy and it will slide right back in easy as well. If that fails I would return it to the Sprint store.