Customers trying to link AccountEdge Basic v2 with Checkout 3.5.7 will encounter an error when trying to configure the ledger. You'll be able to select your company file and application, but will not be able to continue with the configuration. The workaround is to rename the AccountEdge Basic v2 application inside of the Applications folder to AccountEdge Basic. This will allow you to configure the ledger.
This issue is resolved with the release of Checkout 3.6, which is intended to run on Mac OS X 10.6 through 10.9.