Glad to hear some posts are going through. There is rate-limiting. It's a convoluted answer though as there's not a specific '10 requests per minute' type guideline. You can find the full information below. The limits are based off of the amount of users of your app and the specific requests being made:
developers.facebook.com/docs/reference/a...i/api-rate-limiting/
In general though, I can't imagine '2' is the rolling limit for your app. That seems ridiculously low and not something we've heard of before. At the bottom of that page is a Troubleshooting guide which you can use to see which calls, if any, have been rate limited.
The other possibility is if you're making the exact same post. If so, JFBConnect won't make that post. We won't try to duplicate posts for you, so ensure each of your posts has unique text.
Let me know if you find anything out with the rate limiting or narrow down specific cases where things fail. We'll gladly help however we can.
Thanks,
Alex