Losing primary key when linked to Access

I'm having a very strange problem with my Access application. I'm using an Acces frontend application and my data is placed in a MS-SQL 2000 backend database.Because of slow communication between two offices, I have merge replicated my MS-SQL database. I make two version of the frontend, one linked two MS-SQL server 1 and the other to MS-SQL server 2.

When I link the tables in the MS-SQL subscriber database I'm loosing the primary key in many of my tables - some of the tables don't have the problem. I can't see any different in the tables where it keep the key and in the tables where it doesn't. When I look at the tables from within SQL Server Enterprice Manager the key is there, but when I look from within Acces (where it is linked to) it is not. This is resulting in that I cant add records to the tables with missing keys.

I don't see the problem when linking to tables in the MS-SQL publicher database.

Hope somebody can give me an answer on this.

Romanov