System->Preferences->Hardware->Mouse, see the "Motion" tab.
Try starting "amsn" from a terminal and see what errors it produces.
I just tried and got ....
[root@lycoperdon build]# amsn
Error in startup script: can't find package BWidget
"package require BWidget"
(file "gui.tcl" line 15)
invoked from within
Which looks like a missing dependency (FC7 has several).
The command "yum install bwidget tclsoap" (as root) solved this problem.