Handling 2 Way Updates

Hi all, working as an intern at MS for a year (SDET) and I've been asked to find a way of transfering items from one sharepoint lists to another (intranet to extranet) without access to the underlying SQL servers'. So what I've done is use an access databaes as a bridge creating active views of the two sharepoint lists. I wrote a C# console application that executed some SQL on the bridge to copy data between the two sharepoint lists, this was great could handle updates, deletions and additions of new items. Now I've been asked to make this update process 2 way on a certain field (status) I've been trying for a couple of days now and I'm having no joy. The method I was using (polling) allowed for the first couple of status changes (used 2 statements) but then wrote back the wrong way see below for example SQL:

Extranet owned statuses: Declined, Approved, Not Started, In-Progress, Completed.
Intranet owned statuses: Needs Review, MS Declined

UPDATE intranet JOIN extranet ON (blahblah=blahblah)SEt intranet.status=extranet.status WHERE extranet.status IN (all extranet owned statuses);

UPDATE extranet JOIN intranet ON (blahblah=blahblah)SEt extranet.status=intranet.status WHERE intranet.status IN (all intranet owned statuses);

Can anybody tell me where I'm going wrong and offer any suggestions?

Thanks,
Alex