Quote from: skywave on December 31, 2013, 10:01:01 PM

I have a question to the experts

I have twice discovered - solo mining - that I have found a block - cgminer - accepted and so forth - and then the wallet pops up that little incoming message - but when I open the wallet nothing is incoming - not even after a while..!?
Is it possible that someone somehow can interfere with your wallet w/o you knowing it - and then redirect the incoming to an outside wallet..?
if so - how can that happen?

when I have encountered this I have deleted the whole wallet dir except the wallet and conf - restarted the qt and waited for the whole chain to be downloaded.
but I continue to suspect something wrong because I am still losing a lot of coins which I normally mine over one day - not even just a bit less due to increased diff - but a lot less - almost to a standstill..

If cgminer finds a block, the wallet and cgminer have found a 'working solution', however, this doesn't 100% insure that the block will be accepted by the block chain. If another miner has found a 'working solution' at the same time, whichever miner can propagate that information to the network fastest gets the block. The winner will get the reward, and the other miner gets an 'orphan'. This is usually registered in your wallet as a mined block with a '?' beside it for longer than 2 blocks.

This is one of the strongest arguments for mining in a pool unless you have both a competitive hashrate and a good solid connection to the network.

To answer your other question, it is possible for someone to 'interfere' with your wallet under a narrow set of circumstances if your wallet is not encrypted or encrypted with a weak password AND someone has obtained your private key. If this happens your wallet is compromised and whoever has the private key can spend your coins at will.

Always keep in mind that mining calculations are NOTHING but an estimate. It is possible to have a run of bad luck, especially when the network hash rate jumps, and fall in way below the estimated reward. This is exactly why I don't solo mine anymore. I figure solo mining would require somewhere on the order of 1% of the total network hashrate to negate the 'bad luck' risk. Some people have this kind of hashpower, I don't. Add into that the flash mining and it really is a strong case for pool mining. I mined litecoin for months in pools and solo and in my entire mining career I have found a grand total of one block for one pool, never one solo. My calculations predict that I would find one block every 9.5 days ( back when difficulty was under 300). So, it seems to me (and this is an uncalculated, unproven opinion) that there is a 'critical hashrate level' that one must achieve in order to solo mine.

That being said, take a look through your debug.log file to investigate what is happening to these blocks. My guess is that they are being orphaned, but its worth looking into.

[EDIT] All someone needs is your private key, which can be obtained if you don't have your wallet encrypted, or encrypted with a weak password. Encrypting the wallet protects your private key.