Please describe the problem:
The links/mappings between the different business components (invoices,
customers, vendors, employees, jobs, etc) are lost once the file has been saved
in G2.

Steps to reproduce:
1. Create a new file (set of accounts)
2. Create a combination of customers, vendors, employees, jobs, and invoices 
3. Save the file and reopen


Actual results:
Everything appears okay until the file is saved and then reopened.  At that
point if an invoice is opened it has lost the customer, vendor, etc it belongs
to.  A search for a customer's invoices gives zero results. 

Expected results:
If an invoice is opened it should have the customer, vendor, job, etc that it
corresponds in the appropriate field.  A search for a customer's invoices should
return thier invoices

Does this happen every time?
Yes

Other information:
This "corruption" also happens to a files made with G1.8.12 that has been opened
and saved in G2.