1. No clear deadline. Although it's a simple concept, many companies have trouble staying on track. Instead of letting problems grow over time, reevaluate progress each week and make adjustments ahead of an impending disaster three months down the road.
2. Perfection. The site is never going to be completely right. Push it live and learn from customers.
3. Unclear goals to launch. Finish lines need a tangible end point. If the team doesn't know how to win, then it's going to get stuck in circles chasing ideas.
4. Poor project planning. "The easy Photoshop button," "the site that magically fills itself with content," or the "engineering problem that is no big deal." We've all heard (or made) these comments, and they never end well. Pull your team in early and ask tough questions— it's not going to get easier in the middle of the project!
5. Lack of engineering thinking. Websites are moving bits, not dynamic ad boards. The engineer you see as not being a team player probably has a few reasons why the answer is "that won't work"— find out what they are. Look for ways to incorporate engineering thinking into the early phases of a project.
6. No interface talent. Those pages aren't going to just suddenly come together by themselves. Make sure your team is stacked with people who understand how to construct web pages, it's fundamental to a successful web project.