QuickBooks 2009-10 Service Pack 1

QuickBooks 2009-10 DB Server Manager Update is a free update for QuickBooks QBi 2009/10 customers who are using QuickBooks in a multi-user environment.
QuickBooks 2009-10 DB Server Manager Update fixes an issue with the version of the Database Server Manager, which consequently prevented company files being accessed in certain multi-user environments.

If you are getting error message H101, H202, H303 and/or H505 while switching (or if you are already in) multi-user, then this update is for you.