Linked Table and Missing Unique Identifiers ??!?!??!?

[prodtest]

Hi,
I have a stock database that I have been builing as a side project at work and have an issue with linked tables.

I have a transactions table on an SQL server that has its primary key field set to unique identfier, this works fine so long as I input data direct via an adp file.

However when I try and input data direct form a mdb file with linked tables it does not pass the unique number across.
Can someone help as i am stuck on how to generate a unique transaction number for use as a primary key

 

[prodtest]

Sorry hit post before I said:

Any help is greatly recieved

Ben