Problem with Photoshop

[Henry]

CS 8.0-

When i click/drag something to move it it drags anything thats there, not just the layer that im on.
Is there a way i can change it back to not being able to change anything thats not on the selected layer?
If you dont get it, tell me.

[unit_number_43]

make sure your layers aren't linked, and that your document mode is set to RGB.