According to this.
I would have thought a settlement freeze is a reasonable pre-condition. If that can't be held by Israel, then any negotiations could just drag on for years, as more and more settlements are built. According to that, Abbas wants to negotiate. The precondition listed is a reasonable one. He wants to continue from where Olmert left off. That is, the offer that was made before.
http://www.jpost.com/MiddleEast/Article.aspx?id=295224
What looks to you like reasonable preconditions look to me like demands which made to ensure that talks do not start.
The issue of settlement building was introduced as a condition by Obama and taken up by Abbas more than three years ago. At first Bibi refused to condone this, but the he was pressured to halt construction for ten months. Abbas still refused to talk, until the ten months were almost over. After that Bibi refused to extend the period. He is unlikely to agree to a freeze again, because i) he has already done it to no avail, and ii) the subject was not a precondition to previous talks. Abass is well aware of that, and he uses the subject to avoid negotiations.
Why do I think that Abbas wishes to avoid negotiations. Apart of the fact that he did his best to do just that during the last three years, there is also the question of his other demand, namely, that the talks would resume from the offer that Olmert gave him. This condition is a laughable.
The offer Olmert gave Abbas was a final offer from Olmert's viewpoint. Abbas was asked to either accept it, or reject it. (Not literally, minor changes could be made. But the major outline of the proposed deal was final.). It was Olmert's offer, and it expired once he left office. Now Abbas want to START NEGOTIATIONS from this offer. This is a flawed mechanism for negotiations because Palestinians so far, during many rounds of final peace talks, are yet to make a counter offer to Israeli suggestions for a peace agreement. What will happen next time? Will Abbas try to get an improved plan from Bibi, break negotiations, and then demand that talks resume from that point? This is not a mechanism that encourages the compromises that would lead to an agreement.
In any case, the conditions are not going to lead to negotiations and Abbas knows this. Olmert's offer went beyond what any other political leader of a major party in Israel would offer as a final deal. (This include the leaders of Labor and the various center parties.) Abbas already rejected that offer. By demanding that the offer would be the starting point of negotiations Abbas is trying to ensure that there will be no negotiations. He will probably succeed.