Taskbar Switcharoo Feature For Individual Items In Windows 7?

I vaguely recall that when I first got on Windows 7 I was able to do the new feature taskbar rearrangement with all items on the bar, but currently when I try to move one explorer item it wants to move them all, which means I can put a program to the left or right of all explorer windows, but I can't move an explorer window opened later left of any earlier one. Is that a standard limitation? is my memory failing me, or have I maybe changed some feature that does allow explorer items on the taskbar to be shuffled amongst each other, rather than being effectively attached to each other in their present order?