So far it doesn't seem there is any bug causing this. Dev will have to test but it might just be some trouble loading the forum to actually check signature and post count (perhaps new filters from bitcointalk) or other similar problem. It appears to be very intermittent.

Problem is dev had busy schedule. Some new features are needed. I'll make sure failed entries can be retried automatically if they failed at cron (you will receive the same rate as everyone else as it is calculated for the cron before entries are processed. A reprocessed entry will use that same rate.). Other than this issue to figure out, adding that fix should be good enough for now. Dev should be able to add it in the next few days. Other than that nothing seems wrong with tracker so I'll ask wao to go ahead and make payments.

Thank you for your patience.