Hi are you talking the normal eraser or the background eraser?
Normal Eraser:
Check to see what your settings are at, full Opacity, full Density, step set to 1.
Also your eraser can take on any shape or variance like that of a brush tip, so make sure to reset your eraser to normal by clicking the little black arrow in the brush varience dialog window. Or just make sure to pick a preset eraser brush that came with PSP.
Background Eraser: same setting as above but check your sampling and limits and auto tolerance. Those should all be up in the tool bar when you pick the BG eraser, but if you can't see all of them you need to click the little black arrow at the end, which basically means some tool options are hiding over there!!
