I created a fiddle that exemplifies the problem:
This is working exactly as I want it, but the problem is that in IE7 the absolutely positioned span (hover-tooltip-container) starts at the top of the line instead of at the bottom like it does in the other browsers. If you add a border to hover-tooltip-container, you can see this.
This is a problem because I want the tooltip to go up, but the anchor to still be exposed. You should be able to mouse over the tooltip as well, but the gap in IE7 makes this impossible.
If there is any way to get the hover-tooltip-container span to start in the same place on the line in IE7, IE8, and FFX, that would be perfect.
Javascript is not a solution.
I was able to solve the problem by having the “container” element float left and have relative position. This achieves the appearance of breaking out of containers but still provides a reference for the tooltip to go up from.