Since you have CS5 ... you can put the shadow on it's own layer in the layers palette and manipulate it even more. Once you get the basic shadow you want on your object, try the following:
(1) Select the layer in the layers palette
(2) Click the down arrow next to "fx" on the layer
(3) From the drop down menu, select "create layer"
... PS will place the "shadow" on the layer below the object layer ...
Now, you can go down to the shadow itself and manipulate it ... and/or ...
You can nudge the object layer up and slightly right or left to make the object appear further from the page.
Hope this is helpful ...