Mine has been stuck at the same number for 8 hours, yet I see my earnings in each individual block if I go look
sorry to be so picky about this, but I have to earn back my mining hardware, in a limited time, haha
If you have the pre-paid perk enabled (My Account > Donations and perks, the "immediate pay" options at the end of the page), you are getting paid for every block as soon as it is found and gets at few confirmations (I believe, possibly just one).
The last block that appeared in the block list when you posted was at height 237798. The block in the main chain (the "real" one) at this height was from ASICMiner, not BitMinter. Than means it was probably a stale block, and it still show as "processing" in the list until it is found to be stale. Maybe* this will happen when the next block is found, but as far as I understand, this block will never make it to the main chain and miners will not be paid for it (and it's perfectly normal because it yielded no earnings to the pool).
So, basically, I think you have not been paid in the last 8 hours because of a very unlucky round (6 hours), with an unlucky outcome (i.e. stale), followed by another unlucky round (4 hours), and while I wrote these line, we found one at height 237825 (phew!).
Now, the bad luck is probably going to end, and you will see your unconfirmed total increasing (it will be confirmed immediately if you enable the pre-pay perk w/ a small donation).
Finally, if you're not yet aware of how PPLNS works, you had to "fill" the last 10 shifts when you started mining, meaning initial revenues were lower than expected. But should you stop mining now, you will still earn revenues until you don't have any remaining work shares in the last 10 shifts, so it's a "symmetrical" delay in payments when you start/stop mining.
Hope that helps...
tl;dr: We have been very unlucky in the last 8 hours. Keep mining and with some luck your earnings will catch up with expected ones.
*edit: maybe => yes indeed!