issue has resolved itself. for clarification, after more trouble shooting, i found the following:
1. this was not preflight specific, though it was there as well (also in our test app.)
2. new content would not download to a device unless it was added to a new collection.
3. once content had download for the new collection, it was available on the old collection as well.
conclusion: seems as though the mechanism to push updated articles was having an issue.
