taskbar switcharoo feature on individual items

I vaguely recall that when I first got on Win7 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?

it's currently set to 'never combine'