looks like there is still an error in the staking. After hit an stake block the staking dies with these error messages in the log :
2016-07-27 12:33:36 CheckStake() : new proof-of-stake block found
hash: 131ca7ac016a8b4a59d55c77d2aedbfbc96a3ea1a197759e25436addaa28d955
proofhash: 0000000000000000000000000000000000000000000000000000000000000000
target: 0000000000000000000000000000000000000000000000000000000000000000
2016-07-27 12:33:36 CBlock(hash=131ca7ac016a8b4a59d55c77d2aedbfbc96a3ea1a197759e25436addaa28d955, ver=7, hashPrevBlock=7f32a3388d440fa2f64f6896d7da1e5cdc8cb96521acb0617e41c1e099a2dc4b, hashMerkleRoot=325c33ed41fef8bf0074e9e31ee72c304bcb846ea4a565609b194be064e38c00, nTime=1469622816, nBits=1e0fffff, nNonce=0, vtx=2, vchBlockSig=304402201b0334baa08c5e07f9d579f72b471eaedae251d875aecb7a63d8cbe39dc005300220772d80f76d364d5738bdd4928996dc6da3dda59795c28c0f8c8bb432a2e67865)
Coinbase(hash=0b220017171219bc0894d1ce51eb646c6be50d8fdee5a7fbf9c7e422ceca2ce4, nTime=1469622816, ver=1, vin.size=1, vout.size=1, nLockTime=0)
CTxIn(COutPoint(0000000000, 4294967295), coinbase 02e476)
CTxOut(empty)
Coinstake(hash=9302a8513ed87c657bcffd57b04cd058436524b3732ddad9d01729fd81731a45, nTime=1469622816, ver=1, vin.size=11, vout.size=3, nLockTime=0)
CTxIn(COutPoint(3bf67c3c3e, 3), scriptSig=3045022100d9f605980ec7da)
CTxIn(COutPoint(91a47f0713, 2), scriptSig=3044022078387721a2126980)
CTxIn(COutPoint(2523588a95, 2), scriptSig=3045022100ce48ae6cd722b4)
CTxIn(COutPoint(1bdfcc0164, 2), scriptSig=30450221008d48820a19aa4d)
CTxIn(COutPoint(b12060238b, 3), scriptSig=3045022100802793d236b288)
CTxIn(COutPoint(4ea55f1153, 2), scriptSig=3045022100c3bcf9e5186b53)
CTxIn(COutPoint(61406675d6, 2), scriptSig=3044022075dd820216231024)
CTxIn(COutPoint(91bcba38a6, 3), scriptSig=3045022100e1018e1fd632e8)
CTxIn(COutPoint(bf3368d5f2, 3), scriptSig=304402200bc8a7ab3a8e7539)
CTxIn(COutPoint(9bdf6a3bce, 2), scriptSig=3045022100d988d273ed7aa2)
CTxIn(COutPoint(c506311bb2, 2), scriptSig=3044022041c6ab9cd34459e3)
CTxOut(empty)
CTxOut(nValue=3.82228535, scriptPubKey=0330b99c0b2d80a4f3d74968f2d51906fd3efa535491f82caaf295b1e96c05cf74 OP_CHECKSIG)
CTxOut(nValue=0.00369863, scriptPubKey=OP_DUP OP_HASH160 e5a8f835d95138afe2f1e5aab9080aa3f1821a66 OP_EQUALVERIFY OP_CHECKSIG)
vMerkleTree: 0b220017171219bc0894d1ce51eb646c6be50d8fdee5a7fbf9c7e422ceca2ce4 9302a8513ed87c657bcffd57b04cd058436524b3732ddad9d01729fd81731a45 325c33ed41fef8bf0074e9e31ee72c304bcb846ea4a565609b194be064e38c00
2016-07-27 12:33:36 out 3.82598398
2016-07-27 12:33:36 CheckBlock() : Found payment(1|369863) or payee(1|3QJmnh) nHeight 30436.
2016-07-27 12:33:36 CheckBlock() : Found payment(1|369863) or payee(1|3QJmnh) nHeight 30436.
2016-07-27 12:33:36 ERROR: ConnectInputs() : 9302a8513ed87c657bcffd57b04cd058436524b3732ddad9d01729fd81731a45 prev tx already used at (nFile=1, nBlockPos=14708372, nTxPos=14708520)
2016-07-27 12:33:36 InvalidChainFound: invalid block=131ca7ac016a8b4a59d55c77d2aedbfbc96a3ea1a197759e25436addaa28d955 height=30436 trust=5108375382480 blocktrust=1048577 date=07/27/16 12:33:36
2016-07-27 12:33:36 InvalidChainFound: current best=7f32a3388d440fa2f64f6896d7da1e5cdc8cb96521acb0617e41c1e099a2dc4b height=30435 trust=5108374333903 blocktrust=20400889458 date=07/27/16 12:30:58
2016-07-27 12:33:36 ERROR: SetBestChain() : SetBestChainInner failed
2016-07-27 12:33:36 ERROR: AcceptBlock() : AddToBlockIndex failed
2016-07-27 12:33:36 ERROR: ProcessBlock() : AcceptBlock FAILED
2016-07-27 12:33:36 ERROR: CheckStake() : ProcessBlock, block not accepted
2016-07-27 12:33:37 CheckStakeKernelHash() : using modifier 0xfc303d881bfbe613 at height=30435 timestamp=2016-07-27 12:30:58 UTC for block from timestamp=2016-07-26 11:24:00 UTC
2016-07-27 12:33:37 CheckStakeKernelHash() : check modifier=0xfc303d881bfbe613 nTimeBlockFrom=1469532240 nTimeTxPrev=1469532240 nPrevout=2 nTimeTx=1469622816 hashProof=e9d07bf6966da85f56dc6c14a510c770b8718043ee113137d1df88aa2ce8745a
2016-07-27 12:33:37 ERROR: CheckStakeKernelHash() : min age violation
2016-07-27 12:33:37 ERROR: CheckStakeKernelHash() : min age violation
2016-07-27 12:33:37 ERROR: CheckStakeKernelHash() : min age violation
2016-07-27 12:33:37 ERROR: CheckStakeKernelHash() : min age violation
2016-07-27 12:33:37 ERROR: CheckStakeKernelHash() : min age violation
2016-07-27 12:33:37 ERROR: CheckStakeKernelHash() : min age violation
2016-07-27 12:33:37 ERROR: CheckStakeKernelHash() : min age violation
2016-07-27 12:33:37 ERROR: CheckStakeKernelHash() : min age violation
2016-07-27 12:33:37 ERROR: CheckStakeKernelHash() : min age violation
2016-07-27 12:33:37 CheckStakeKernelHash() : using modifier 0xfc303d881bfbe613 at height=30435 timestamp=2016-07-27 12:30:58 UTC for block from timestamp=2016-07-25 13:24:00 UTC
2016-07-27 12:33:37 CheckStakeKernelHash() : check modifier=0xfc303d881bfbe613 nTimeBlockFrom=1469453040 nTimeTxPrev=1469453040 nPrevout=2 nTimeTx=1469622816 hashProof=2e2aec1f5085a96332040b81b586dc05bc5c8900cc6f85f8c5eec026acda82ec
2016-07-27 12:33:37 CheckStakeKernelHash() : using modifier 0xfc303d881bfbe613 at height=30435 timestamp=2016-07-27 12:30:58 UTC for block from timestamp=2016-07-22 21:34:24 UTC
2016-07-27 12:33:37 CheckStakeKernelHash() : check modifier=0xfc303d881bfbe613 nTimeBlockFrom=1469223264 nTimeTxPrev=1469223264 nPrevout=3 nTimeTx=1469622816 hashProof=cf92debc2f603d3017cdfba5e8c0d738196783b2bccd827ae13450bd31997440
2016-07-27 12:33:37 Masternode payment to MUqVPa59DzNJxLsyZyQz4rTU5HFpHHui9o
the log is filed up with these messages and after some hhours it stops but no more staking occurs.
restart the wallet helps - this was mentioned several times.
regards
P.S. Thanks for the upvote of my steem posts :-)