The settings seem to be affecting each layer simultaneously. If I add a drop shadow to layer 1 with settings X and then try to add a drop shadow to layer 2 with settings Y, settings X will change to become settings Y. It's possible to see this happen as I change the angle in setting Y and watch the graphic. Layer 1's settings will move along with layer 2's settings.
I've tried ticking on or off various options concerning blending options in general and the drop shadow in particular with no luck yet.
I have also checked in the memories under "Photoshop: Tips and Tutorials" and "Photoshop: Problems and Errors". Tips and Tutorials had two entries concerning drop shadows but no relevant information to my problem; Problems and Errors had none.
If there's an existing post on this anywhere, I'd really appreciate it if someone could point me to it. If there isn't, then it'd be great if someone could help explain what I might be doing wrong or what I need to change.
Just for reference: My Drop Shadow Settings
txvoodoo was kind enough to explain the problem and offer a solution. Thank you very much!