Can you bisect it?
working on it
I let it run for a couple hours. Each rig is running the same pools, same settings, started at the same time
bfgminer version 5.2.0-2-ga488b3f - Started: [2015-08-16 01:13:21] - [ 0 days 01:57:58]
[M]anage devices [P]ool management [ S]ettings [D]isplay options [H]elp [Q]uit
Pools: 6 (0,1,2,3,4,5) Diff:15m-125m + LU:[03:11:45]
Block: ...fddf34e6c0049363 Diff:66 (477.3M) Started: [03:12:04] I:?
ST:21 F:21 NB:853 AS:0 BW:[254/122 B/s] E:0.29 BS:348
3/12 | 247.6/262.7/217.5Mh/s | A:5027 R:1417+66( 18%) HW:595/.53%
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KNC 0: | 85.84/87.31/71.14Mh/s | A:1811 R: 475+ 3( 19%) HW:185/.50%
KNC 1: | 79.69/87.93/72.80Mh/s | A:1712 R: 553+ 1( 18%) HW:138/.37%
KNC 2: | 80.81/87.51/73.65Mh/s | A:1505 R: 397+62( 16%) HW:272/.73%
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[2015-08-16 03:12:02] Rejected 000b1656 KNC 1a pool 3 Diff 90m/15m (Job not found.)
[2015-08-16 03:12:03] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:03] Rejected 00222722 KNC 1a pool 3 Diff 29m/15m (Job not found.)
[2015-08-16 03:12:04] Accepted 0000cc77 KNC 2c pool 1 Diff 1/31m
[2015-08-16 03:12:04] Network difficulty changed to 66 (477.3M)
[2015-08-16 03:12:04] Stratum from pool 3 detected new block
[2015-08-16 03:12:06] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:06] Rejected 001e3974 KNC 0c pool 3 Diff 33m/15m (Job not found.)
[2015-08-16 03:12:07] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:07] Rejected 00215840 KNC 0b pool 3 Diff 29m/15m (Job not found.)
[2015-08-16 03:12:09] Accepted 00180ff4 KNC 2c pool 1 Diff 41m/31m
[2015-08-16 03:12:09] Pool 5 stale share detected, submitting as user requested
[2015-08-16 03:12:09] Accepted 0007427c KNC 1d pool 5 Diff 137m/125m
[2015-08-16 03:12:09] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:09] Rejected 0003220f KNC 0b pool 3 Diff 319m/15m (Job not found.)
[2015-08-16 03:12:10] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:10] Rejected 00033b37 KNC 0d pool 3 Diff 309m/15m (Job not found.)
[2015-08-16 03:12:10] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:10] Rejected 00021b39 KNC 0c pool 3 Diff 474m/15m (Job not found.)
[2015-08-16 03:12:11] Pool 4 stale share detected, submitting as user requested
[2015-08-16 03:12:11] Accepted 00034bb3 KNC 1b pool 4 Diff 303m/125m
[2015-08-16 03:12:11] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:11] Rejected 000f5cd0 KNC 0b pool 3 Diff 65m/15m (Job not found.)
[2015-08-16 03:12:11] Accepted 0011d5a0 KNC 2d pool 1 Diff 56m/31m
[2015-08-16 03:12:12] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:12] Pool 5 is sending mismatched block contents to us (0 is not 8-15)
[2015-08-16 03:12:12] Rejected 0027d276 KNC 1a pool 3 Diff 25m/15m (Job not found.)
[2015-08-16 03:12:13] Pool 5 stale share detected, submitting as user requested
[2015-08-16 03:12:13] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:13] Accepted 0000afc5 KNC 2b pool 5 Diff 1/125m
[2015-08-16 03:12:13] Rejected 0034e8c6 KNC 1a pool 3 Diff 18m/15m (Job not found.)
[2015-08-16 03:12:14] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:14] Pool 3 stale share detected, submitting as user requested
[2015-08-16 03:12:14] Rejected 000bd22e KNC 0d pool 3 Diff 84m/15m (Job not found.)
[2015-08-16 03:12:14] Rejected 001f2e8d KNC 0b pool 3 Diff 32m/15m (Job not found.)
bfgminer version 5.1.0-titan-2.00 - Started: [2015-08-15 18:15:46] - [ 0 days 01:58:15]
[M]anage devices [P]ool management [ S]ettings [D]isplay options [H]elp [Q]uit
Pools: 6 (0,1,2,3,4,5) Diff:31m-125m + LU:[03:11:45]
Block: ...5ef68b619529de76 Diff:64 (460.6M) Started: [03:12:15] I:?
ST:21 F:22 NB:1165 AS:1 BW:[233/104 B/s] E:0.38 BS:120
3/12 | 281.7/263.3/259.3Mh/s | A:5376 R:120+2(1.9%) HW:478/.43%
----------------------------------------------------------------------------------------------------
KNC 0: | 98.15/87.23/86.70Mh/s | A:1814 R: 16+1(1.0%) HW:200/.54%
KNC 1: | 86.12/87.77/86.40Mh/s | A:1743 R: 36+0(1.9%) HW:145/.39%
KNC 2: | 95.35/88.23/86.15Mh/s | A:1821 R: 68+1(2.7%) HW:134/.36%
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[2015-08-16 03:11:45] Pool 1 is sending mismatched block contents to us (0 is not 2-3)
[2015-08-16 03:11:48] Accepted 0004ba69 KNC 1c pool 4 Diff 211m/125m
[2015-08-16 03:11:52] Pool 0 is sending mismatched block contents to us (0 is not 8-15)
[2015-08-16 03:11:52] Pool 5 is sending mismatched block contents to us (0 is not 8-15)
[2015-08-16 03:11:52] Pool 4 is sending mismatched block contents to us (0 is not 8-15)
[2015-08-16 03:11:56] Accepted 00121db7 KNC 0a pool 3 Diff 55m/31m
[2015-08-16 03:11:58] Accepted 0007ed43 KNC 2a pool 4 Diff 126m/125m
[2015-08-16 03:11:58] Accepted 0006ed6c KNC 0b pool 5 Diff 144m/125m
[2015-08-16 03:12:00] Accepted 00069a22 KNC 1b pool 2 Diff 151m/125m
[2015-08-16 03:12:00] Accepted 00074108 KNC 1a pool 2 Diff 137m/125m
[2015-08-16 03:12:00] Network difficulty changed to 66 (477.1M)
[2015-08-16 03:12:00] Stratum from pool 3 detected new block
[2015-08-16 03:12:03] Accepted 000402d6 KNC 2a pool 4 Diff 249m/125m
[2015-08-16 03:12:03] Accepted 0005027e KNC 1b pool 2 Diff 199m/125m
[2015-08-16 03:12:04] Network difficulty changed to 66 (477.3M)
[2015-08-16 03:12:04] Stratum from pool 3 detected new block
[2015-08-16 03:12:04] Accepted 0005910e KNC 1a pool 2 Diff 179m/125m
[2015-08-16 03:12:04] Accepted 00012b05 KNC 2a pool 4 Diff 856m/125m
[2015-08-16 03:12:09] Accepted 001d412e KNC 0d pool 1 Diff 34m/31m
[2015-08-16 03:12:10] Accepted 0006c4ac KNC 2d pool 2 Diff 147m/125m
[2015-08-16 03:12:10] Accepted 0004bbc5 KNC 1b pool 2 Diff 211m/125m
[2015-08-16 03:12:11] Accepted 0007b28d KNC 2a pool 4 Diff 129m/125m
[2015-08-16 03:12:12] Accepted 00063783 KNC 2c pool 4 Diff 160m/125m
[2015-08-16 03:12:13] Accepted 00010dc0 KNC 0b pool 5 Diff 949m/125m
[2015-08-16 03:12:15] Network difficulty changed to 66 (477.6M)
[2015-08-16 03:12:15] Network difficulty changed to 64 (460.6M)
[2015-08-16 03:12:15] Stratum from pool 3 detected new block
[2015-08-16 03:12:17] Accepted 00024b79 KNC 2a pool 4 Diff 435m/125m
[2015-08-16 03:12:20] Accepted 00065263 KNC 1c pool 2 Diff 158m/125m
[2015-08-16 03:12:22] Pool 0 is sending mismatched block contents to us (0 is not 8-15)
[2015-08-16 03:12:22] Pool 5 is sending mismatched block contents to us (0 is not 8-15)
[2015-08-16 03:12:22] Pool 4 is sending mismatched block contents to us (0 is not 8-15)
[2015-08-16 03:12:23] Accepted 0001e8a2 KNC 1c pool 2 Diff 523m/125m
[2015-08-16 03:12:24] Accepted 0006c181 KNC 2b pool 2 Diff 148m/125m
[2015-08-16 03:12:25] Accepted 00013280 KNC 1d pool 3 Diff 835m/31m