ARTROOM  Might the reason for your issues be this (as stated in the installer)

Important note for Final Cut Pro HD Users

You must first disable “keyboard Navigation” in Mac OS X before using. the “play rate transport controls” for Final Cut HD. Here is how you do this:

1. In the Apple, menu select “System Preferences”.

2. Select the “keyboard and Mouse” icon.

3. Unselect “Keyboard Navigation”.

Users of earlier versions of Final Cut Pro will need go to www.contourdesign.com/shuttlepro/shuttle_downloads.htm, and download settings Final Cut Pro Edit/ Viewer and Final Cut Pro Edit/ Timeline.  
(Version 2.1.2)

ANONYMOUS  Had same problem. Could not fast forward or fast reverse. Although settings are correct for FCP, forward and reverse shuttle did not function.

10.3, G5 dual 2.0, FCP 4  
(Version 1.4)

ANONYMOUS  shuttle pro in shuttle mode only do slow

motion foward & reverse.

os x 10.2.8

final cut pro 3.0.4

avid xpress dv 3.5.4

shuttle pro version #1.

will contact shuttle maker to know if it is a

bug or configuration problem....

but shuttle pro should be able to fast search

foward & reverse at multiple speeds....  
(Version 1.4)