I kinda see the idea.. i think the highlighting doesn't take advantage of changing the text alphas and such.. which would perhaps make it more obvious.. as well.. it seems to get stuck because of what seems to be the hyperlinks mouseover event not propagating to its parents, thus they don't always see the mouses over event if you hit managed to get inside the rounded rectangle and over the hyperlink before the mouse event is updated.. (which also seems to be really easy)..

It's scary that the mouse events are THAT slow though..

Edit: Some small animation easing wouldn't hurt either.. it always takes that 'edge' off and makes things a bit more friendly.