MDA Vario iii - All txt messages are sent &...

Question

Driving me crazy - everytime I send a text it comes up that I have started a conversation and any responses I receive back come into my inbox as part of this conversation. (bit like MSN messenger, but thats not what I want) - No messages therefore get saved in my sent box - even though this is enabled and worst still I contacted technical support and they couldn't help. My husband has exactly the same phone (delivered at the same time) and his phone is fine - yet all our settings appear the same. Has anyone else had this issue and if yes, what do you do to resolve it.