Ahh, thanks for the very helpful debug output.
I've updated the miner to b12 and committed into the repository.
b12 fixes a known bug with not regenerating the nonce time frequently enough for ypool. The miner now resets its time nonce every minute instead of every block.
This slows down the miner a bit. Sorry - but it should compensate by not having invalid shares as often. You might find that reducing -s slightly helps.
But there may still be lingering buts causing this "not a valid prime" error. I'm going to keep digging, and will work on getting some of that speed back in b13.
-Dave
Are people seeing this on Linux also?
yes.
2014-03-23 08:58:23.532409175 [07:39:52] Share found! (Blockheight: 24610)
2014-03-23 08:58:25.432824705 [07:39:54] 2ch/s: 30.3795 3ch/s: 1.9480 4ch/s: 0.0681 Shares total: 532 / 511
2014-03-23 08:58:33.432838812 [07:40:02] 2ch/s: 30.3808 3ch/s: 1.9483 4ch/s: 0.0681 Shares total: 532 / 511
2014-03-23 08:58:34.672120815 [07:40:03] Share found! (Blockheight: 24610)
2014-03-23 08:58:41.434825115 [07:40:10] 2ch/s: 30.3809 3ch/s: 1.9485 4ch/s: 0.0682 Shares total: 533 / 512
2014-03-23 08:58:49.435824174 [07:40:18] 2ch/s: 30.3814 3ch/s: 1.9489 4ch/s: 0.0682 Shares total: 533 / 512
2014-03-23 08:58:56.817584732 [07:40:25] Share found! (Blockheight: 24610)
2014-03-23 08:58:57.435830082 [07:40:26] 2ch/s: 30.3820 3ch/s: 1.9490 4ch/s: 0.0684 Shares total: 534 / 513
2014-03-23 08:58:57.751832129 Invalid share
2014-03-23 08:58:57.751847632 Reason: CheckProofOfWork() : not valid pow
2014-03-23 08:59:05.435828594 [07:40:34] 2ch/s: 30.3828 3ch/s: 1.9487 4ch/s: 0.0683 Shares total: 534 / 512
... no new shares found till I restarted the process
2014-03-23 09:01:21.381338929 [07:42:50] Share found! (Blockheight: 24612)
2014-03-23 09:01:21.450835838 [07:42:50] 2ch/s: 30.3662 3ch/s: 1.9490 4ch/s: 0.0681 Shares total: 535 / 513
2014-03-23 09:01:22.209827519 Invalid share
2014-03-23 09:01:22.209846968 Reason: CheckProofOfWork() : n not prime
2014-03-23 09:01:29.450829867 [07:42:58] 2ch/s: 30.3649 3ch/s: 1.9488 4ch/s: 0.0681 Shares total: 535 / 512
2014-03-23 09:01:31.656831570 Ping 656.0ms (Average 912.0)
2014-03-23 09:01:37.451826894 [07:43:06] 2ch/s: 30.3659 3ch/s: 1.9492 4ch/s: 0.0681 Shares total: 535 / 512
2014-03-23 09:01:45.453825500 [07:43:14] 2ch/s: 30.3656 3ch/s: 1.9491 4ch/s: 0.0681 Shares total: 535 / 512
2014-03-23 09:01:53.455857748 [07:43:22] 2ch/s: 30.3648 3ch/s: 1.9488 4ch/s: 0.0681 Shares total: 535 / 512
2014-03-23 09:02:01.073502585 [07:43:30] Share found! (Blockheight: 24612)
2014-03-23 09:02:01.289827815 Invalid share
2014-03-23 09:02:01.289841922 Reason: CheckProofOfWork() : n not prime
...
2014-03-23 09:24:07.587949574 Reason: CheckProofOfWork() : n not prime
2014-03-23 09:24:09.612825465 [08:05:38] 2ch/s: 30.2689 3ch/s: 1.9400 4ch/s: 0.0685 Shares total: 560 / 512
restarted, all works ok:
2014-03-23 09:25:18.179824577 [00:00:56] 2ch/s: 23.3326 3ch/s: 1.0971 4ch/s: 0.0000 Shares total: 0 / 0
2014-03-23 09:25:18.686221800 [00:00:56] Share found! (Blockheight: 24628)
2014-03-23 09:25:26.179830232 [00:01:04] 2ch/s: 24.1280 3ch/s: 1.2160 4ch/s: 0.0640 Shares total: 1 / 1