Group projects are a good learning experience for advanced students. They invariably generate some tense moments as some team members feel the work and credit are not shared equally. I insist, however on giving the entire group the same grade. The rationale for this is that in many situations, individuals have to learn to work together for the common good. Part of learning to be successful professionally is learning how to deal with people; how to negotiate, how to be assertive without alienating others, how to accept compromise, and how to deal with irrational people (you will certainly encounter plenty of irrational clients). While the outcome is never certain, the saving grace is that such group situations are temporary.
One student approached me before grades were given out on a group project and wanted me to konw that he/she was largely responsible for the work done an the project, and the other team member did not pull his/her weigth. I thanked the student reiterated that it did make any diffference in the grading. It turned out that that projct was one of the higest-rated ones by the professional critquers. Upon reflection, it occured to me, that that kind of group disloyalty is never apprecatiaed and in most cases reflects negatively on the person airing those sentiments.
In short, the most professional approach is to show as few cracks as possible in the group facade. You may vow never to work wtih said individual again; but while the group is working, it the duty of every member to do what is necessay to make it a success. Cajole, encourage, shae, persuade the others to do their part, but alimately, the entire group in in the same boat. Exert leadership if it is necessary, take up the slack if necessary, but the show goes on.