If they all added entries at precisely the same moment -- and I mean _exactly_ (to the 1/1000th nanosecond) then their might be an issue. How many secondary systems are there?
Have you considered a program other than Quickbooks?
http://www.marketplace.intuit.com/Ap...168&CatID=#FAQ
That driver enables Excel, Access, Visual Basic, etc. to use the DBMS file format that QuickBooks uses... maybe excel would open quicker? You could use Quickbooks on your primary machine, but use the dirver and Excel (for example) on your secondary machines.