I just reached Vergen and accepted all of the jobs on the notice board (Harpy Contract, Harpy Queen Contract, Proclamation of Closure of the Mines, Baltime Considered Dead and Investigator Needed) but the only one that appeared on my journal was "Harpy Contract". Is there any problem with the remaining quests or is it how it's supposed to be?

I'm also experiencing this. I tried an older save to see if it was a one off thing but the same thing occurred.

Only the harpy contract shows up in the journal.

I'm experiencing the same thing. Solutions?

you have to read books on monsters involved in the quests before they appear for you, since you can't fight the monsters if you don't know how, the same thing happened in flotsam until you bought books from the dwarf and read them.

and for other quests sometimes you have to talk to another npc before they appear if i remember correctly.

For me contracts in Flotsam appeared in journal without reading books.

I have the same problem with the contracts in Vergen, did you manage to solve it?

Some of the contracts are only for information which might lead you to quests.

Yeah I did all the quests in Vergen. Basically, you will get all the quests whilst doing the main quest. I could only accept the Harpy Queen contract after receiving the key to the quarry. But you can just kill the harpy queen and then return to the noticeboard and accept the quest, which will result in the completion of the quest. You'll get the infested mines quest by Cecil before venturing into the caves, etc.