Syncing Contact between T3 & LD

[Stag]

As I am new to your forum let me say Hi to all of you.

Now that I have introduced myself I hope that someone can help with my small problem.

I have an old T3 which I carry around with me as it has all my contact details etc on it. I also have a new LD and I want to keep the contact data in sync between both machines. As they are both set up on different computers I thought that I could beam the contact data from one to the other using the IR.
This works except that all the records are duplicated on the receiving machine in other words it just dumps the data on top of the existing data so all the records are repeated. Is there any easy way to sync both machines so that they will both have the same data?

I have thought of deleting the contact data on the receiving machine - but I am not sure exactly which data files to delete.

Any help would be gratefully appreciated

Stag