Eraser Tool ticking me off!

I think i did something, changed a setting or something. My eraser tool won't erase. It keeps making a black mark. I changed the color to white, restarted, (because i always do that when something weird is going on). I have been messing around in PhotoShop since i found this site, maybe i screwed i up. Can anyone help me?

Make sure that you have the erase tool set to just erase and not the other two options (least I remember it as two). There should be a black arrow icon on the tool bar that when hovered over for a while, relveals the other options.

If you already know this, sorry.

no hermit that wasn't it. i changed the background color to white also and i was able to erase. but i shouldn't have to keep changing the color from black to white when i'm working on a bitmap piece of artwork should i? Black being the pencil tool and white the eraser tool.

The eraser tool should be erasing pixel information in a layer, not painting over them. If you're erasing something and there's black in it's stead, then it could be one of two things: a. You're erasing the Background layer and the background color is set to black, or b. You're erasing something and there's a black area under the layer you're working in.