All working fine for me

Your hasharate on the pool is calculated from your shares in the current round. The longer the round, the more the shares and the more precise the result. But when you connect during the round, your shares are divided by the round time already elapsed, so the result is lower. It then increases slowly, as does the ratio (your time in round round time so far).

In Slush's system, you're paid for recent shares. That means, after some 15 minutes in round, you're paid almost full refound for your hashrate, when block is eventually found. OTOH, when you leave the pool before the round ends, your shares expire quite quickly.

And when Slush turns around, the hashrate can drop to zero for a moment, at least until it is on his sight again. :-)

Seriously:
The hash rate on the pool is calculated from one's shares, while the miner displays its hashrate as the actual number of hashes it has calculated. So the latter is more precise, as the pool has less information (less numbers), especially when new round has just started. The ratio (number of shares number of hashes computed) depends on your personal luck and varies in time. So will vary your "hashrate" displayed on your pool account page.

[edit] In fact, your displayed "hashrate" is your (difficulty >= 1) share rate, multiplied by 2³². As share rate is usually displayed per minute, the resulting number has to be divided by 60 to obtain hashrate in H/s, and by another million, to get MH/s.
So:
MH/s = Shares/min * 2³² 60 10⁶
MH/s = Shares/min * 71.5827882666...
In other words, for each share/min you need (more than) 71 MH/s.

Yes same here

But on the bright side we have just found our 14th block today so far!

Thanks for the explanation (and others too!)

I have to read up on Slush's method. I see something here, on the score based reward system (linked from their site): https://bt.irlbtc.com/view/1976.msg50002#msg50002

Is there any other information elsewhere?

Thanks again
IAS

yeah it didnt count 1 or 2 of my miners. I guess a server didnt report its data...except the shares seem to be correct. cant be connection issus or the shares wouldnt be up to par. so only way that is possible is if we suddenly jumped to 21th/s during that block... or slush calculator messed up.

18720   2013-06-23 13:23:14   0:06:10   1733441   333   0.00301187   242945   25.00350000    73 confirmations left
18716   2013-06-23 09:02:49   0:06:28   1630529   295   0.00439307   242916   25.12530000    44 confirmations left

stupid 18th/s! those should be .006x's!

I have just over 0.02 NMC and it seems like you need 0.05 to get it through automatic withdrawal. Anyone know whether there is a way to manually withdraw the 0.02 NMC?

18720 is fixed, but 18717 isn't.

18717   2013-06-23 10:16:59   1:14:10   18699760   27744   0.01717210   242928    25.16590000

Great day at Slush! Wouldn't it be awesome if months luck goes above 100% 

Yours got fixed. (or you've gotten even more  ) Wonder why mine isn't  

Any idea when Slush will add NMC to stratum server just like BTCGuild?