Why can't I see texted messages from one contact unless I go to compose?

I texted with one person several times a day on my BB Classic. I never delete the chat. The other week I stopped getting notifications of new messages. When I looked in the text message area no new messages showed. I then went to Compose a message to her and it showed me her last few messages and our history. We've been texting the past few days but I always have to go to Compose to see her message. I get no notification if she texts me.

This does not happen with any other contact. I tried to delete her contact and re-add but it just brings back the history and everything.

Any assistance? I tried restarting.

Thanks