While earnings will often appear in seconds, and be paid in minutes, the actual delay before task completion is reported to CoinWorker can sometimes be much longer. The task back-end FAQ (accessible via the 'Help' -> 'FAQ' dropdown in the task pane) says: "Typically, there is a slight delay between submitting your answers and receiving your reward on our tasks. That delay may be as small as 15 minutes or as long as two days after offer completion." In operation so far, it's usually seemed to be way less than 15 minutes, except on a couple occasions where there seemed to be a pause that was later caught-up on.
If they don't appear soon, DM me your pay-address and I'll look more closely to see if they were mis-logged somewhere else.
Fair enough.
The reason I asked was because the first time a payment didn't appear on the website instantaneously was also the first time I used an extended address, so I though the two might be connected.
EDIT: After waiting ~7 hours for my payments, I decided to try completing a task with my non-extended address. Once I finished, all the money I earned in the past 7 hours (4*3, 1*4) immediately appeared as a single payment on the website.
EDIT2: Everything seems to be working properly now.