black healthbar

Dunno why this is happening, but its happened twice now, mid game my healthbar and the healthbars of the people in my party window, turn black, so i cant see my health bar going down, cant remember what button i pressed last to try and reverse it, very annoying, have to restart game (not just log out and in either, full restart).

Any ideas, did a search for black and healthbar but no joy

Hopefully

Legendel Firestart

anyone, happened again today

please

well what is it, you having an unsuported graphics card or something? If so, post specs, if not then flood guild wars outposts for answers