I played the "unofficial patch" Version and didn't encounter the problem. (Payed Hal Taffin and found Interplanetary Aid after that)
It is also mentioned here:
By the time I installed the unofficial patch, it was too late. The event already occurred, and the patch doesn't fix the problem after the Hal Taffin encounter if you've paid him.
I have just finished the main quest line, I really enjoyed it, but besides that the game is pretty dated and flawed compared to other space sims from that time.
I really liked the game, mainly because there was more variety in missions then in Privateer 1. The downside is that there are nowhere nearly enough plot missions and there are too many bugs. In addition to the one I already brought up, there were at least three missions I failed because the game wouldn't let me complete them (thankfully none of these were plot missions)
Also the game basically forces you to be a good guy most of the time. Being a black market arms dealer is too much of a hassle and not profitable enough to be worth it. And you don't even have the option to be a pirate (you can't blow up civilian ships and take their cargo). While I liked having the option to hire a cargo ship, I didn't like that it was necessary in order to carry any cargo at all. I should have been able to buy a ship that carries cargo on its own like in the first game.
Also, it was frustrating that commodity prices between planets were not posted anywhere in the game itself, nor could you look at the map while you're on a planet. That made it hard to determine your mission routes and how to maximize profit from cargo sales