Hi LJR,
It would be difficult for us to know exactly why your transactions haven't recently being syncing over without more information. For starters, I would suggest checking your Conflicts, by going to Quickbooks->Resolve Conflicts, and see if these transactions that aren't syncing over show up here. I have provided a link here to a help centre article that should help explain how to resolve your conflicts in some detail. Make sure your transactions do not have "Wait for sync Approval" checked off if they are not syncing over to Quickbooks. From Quickbooks->Synchronize, verify your Full Synchronize settings are set appropriately for you, for example, make sure the "Perform daily Full Syncronization" option is set to a time that your Quickbooks file will be open. You an also verify your Full Syncronization is working right away by choosing the "Sync now" option beside the Full Syncronization area at the top of this screen.
Please go through the information I mentioned above to see if this helps you figure out why not everything is syncing correctly. If you are still having issues, post here with anything further you can find out from the conflicts or what is different about the transactions that aren't syncing over.
-Ben