Fat lines in P3: Powers versus symbolic powers

We study the symbolic and regular powers of ideals I for a family of special configurations of lines in P3. For this family, we show that I(m)=Im for all integers m if and only if I(3)=I3. We use these configurations to answer a question of Huneke that asks whether I(m)=Im for all m if equality holds when m equals the big height of the ideal I.