Dynamics GP Integration Manager - "Distributions are Unbalanced"

When you try to integrate a Journal Entry, you end up getting a number of single line unbalanced journal entries instead of a proper multi-line balanced journal entry.

1. Create two data files, a header and a detail
2. Make sure the header has a single number for the journal number - this is your key field
3. Make sure the details have a number that corresponds to the header - this will join to the key field i nthe header
4. Add both files as source files
5. Join them on the key field in the relationship window
6. In the entries subfolder, change the data source to use the line detail file