[rozwado1]

If I have a conversation open with a person (even if I exit back to the home screen), there's no audible alert/red icon notification if they send a new text. Even if my phone goes to sleep and the SMS app has an active conversation open I receive no notifications - so I have to open the app and check all the time to see if the last person I texted sent a new one.

Is this normal, or do I need to restore my phone?

[Heavy Fluid]

Mine does the same thing. Kind of annoying.

[MRTrauffer]

When the SMS app is left open, and as long as the screen hasn't gone to sleep mode, it'll play a quieter sound, similar to the default sound for an incoming message in iChat. I've missed many SMS messages this way as well. I'd really like to set a custom sound as an alert, but that's another topic.