'Add' Export option in Data Management not accumulating data into the cube intersection

Hi All,

We've created a data management process to load data from a file and export it into our application. After the import phase into Data Management there are 23 records that we would expect to accumulate when choosing the 'Add' Export Mode to give us a summarised value of 381 however we are getting a random value of 47 written into the intersection in the cube. Any thoughts as to what might be causing this:-

In DM:-

In Cube:-

The '47' seems to me to be totally random, maybe it's been a very long week but any thoughts would be welcome.