Help me.... Invisible character...?

[finiti]

I got told by another player that I'm invisible? I hadn't noticed anything until they said something. They could see my gear and stuff once they examine me and (obviously) could still select me and cure me.
I ran past some hostile enemies as a test and none of them attacked me. I can still attack and take damage.
I don't use cheats, at least none that I know of... I have downloaded a couple of programs that were supposed to help with lag (which they didn't) but that was awhile ago now.
Please help :c
<edit> sorry if this is in the wrong catergory :c