Why Does PS 7 Create a New Layers Automatically?

I just installed PS 7 after using PS 5.5 for years. I want to keep all the lines I add in an image on one layer, but it is creating a new layer every time I create a line. I can't figure out how to stop it from automatically creating all these layers.

Also, after setting my options for the shape of the arrow, the next time I open PS 7, it has returned itself to its default setting.

Thanks.

When you use the line or any of the shape tools, to avoid creating a new layer, in the top left choose the "Fill Pixels" option.

Thanks graffiti!

You're welcome.