Yes, some of the sculpting opportunities have been like this since the beginning. The one where your Sim has to deliver a masterpiece sculpture to city hall is one that pays nothing, and I don't remember which other ones as well. One that I do remember getting paid for is the one where you have to deliver x number of wooden sculptures to the Warehouse; apparently City Hall doesn't pay its bills, but the criminals do.
I don't know of any fix for this, ejnarts. I just avoid sculpting opportunities except for the ones I remember getting paid for in the past.