combox 与 arraylist

语言：C#
开发软件：Visual Studio 2008
问题：
多个combox绑定了同一个arraylist作为数据源后，改变一个combox的选项，全部combox的选项跟着改变。

ArrayList hour = new ArrayList();
ArrayList minnite = new ArrayList();

for (int i = 0; i <= 23; i++)
{
hour.Add(i);
}

for (int i = 0; i <= 59; i++)
{
minnite.Add(i);
}

//添加‘小时’选项
this.frisr_star_h.DataSource = hour;
this.frisr_end_h.DataSource = hour;
this.second_star_h.DataSource = hour;
this.second_end_h.DataSource = hour;
this.thrid_star_h.DataSource = hour;
this.thrid_end_h.DataSource = hour;

//添加‘分钟’选项
this.frisr_star_m.DataSource = minnite;
this.frisr_end_m.DataSource = minnite;