I'm currently looking into some unusual results from slush's pool payouts. Most blocks on which I complete work (shares) receive the appropriate payouts however some display shares completed but no payout amount.
A screenshot of this issue can be found at https://docs.google.com/file/d/0B_G2Isi7ITVMR25OcnRBYXkwams/edit?usp=sharing .
worker name: brinebold.worker1
uasername: brinebold

Can anyone explain this behavior. Please don't just blindly guess though. If you can't test your theory or provide a definitive answer, please move along.

I don't think these are stale shares because the odds of every single one of hundreds of shares being stale in the same block and this issue occurring on multiple blocks seem incredibly unlikely.
I don't believe this is a case where no work was successfully submitted because I was apparently awarded shares by the pool.
I don't think this is a case of simply being rounded down to 0 because I don't meet the minimum for a payout because the division works out to more than other blocks for which I have received a payout.
I don't think there is a problem with that blockchain, for example, it was rejected by the bitcoin swarm, because other people received a payout for one of these blocks.
These aren't simply unconfirmed blocks because there are blocks that are confirmed that also have shares but 0 payout.

However, if you can find some way to confirm any of those theories, I'd be glad to try it.

I had that yesterday - a reward of none for a few hours but it git fixed after.

It's obvious that you put Difficulty setting on pool's web-site to 128. That means that your miners will not send ANYTHING unless they collect at least 128 shares. Only after that they will send them to the pool to request some reward.
To resolve your issue - decrease difficulty setting to 1.

P.S. Yes, I know, that actually difficulty works in some other way, but it's the most easy way to explain its meaning and why its better to put 1 on slow miners.

Interesting, so shares actually drop to 0 value if the round goes long enough? I realized they were weighted toward later submissions but not to the point at which early shares would be worth 0. I was expecting a logarithmic curve.

Between this and what the other poster suggested (that my difficulty is set too high) I think I may have pieced together the cause (yours) and the fix (his). Testing now.

I'm pretty sure it has more to do with the time between shares, as opposed to where the share came in the round.  But it sounds like you have it figured out now...

getting a lot of connect/disconnects from pool.  Is everything ok?

Stratum and getwork servers crashed, looks like issue in datacenter, but I have no more information yet. Stratum looks recovered now, I'm working on Getwork.

Two blocks found and I'm still not able to get reconnected. A bad day gets worse. Thanks for trying to fix things Slushy. I hope it gets fixed quicker than my wallet. It has been down for almost a week. Search for an answer everywhere and nothing.

same here