User Action doesn't keep replacement variable

All:

I have set up a user action to execute a home-grown command that I use
for transferring data files from the IFS to DB2 physical files
(variation on CPYFRMSTMF command).  I am using a replacement variable so
that I don't have to type in the whole path name for the command.  Here
is the command:
        CPYFRMIFS PATH(&FP)

Replacement variable &FP is supposed to bring in the entire path of the
file.  When I start WDSc and attempt to use this command, the prompted
command window shows my path parameter with the value "&FP" (minus the
"s).  If I then go to Work With User Actions, retype the &FP in the
command, apply and select the user action again, it works just fine,
replacing the "&FP" with the path of the file I selected.

The problem is that I have to do this the first time I use this user
action after starting up WDSc.  Has anyone else seen a similar
situation?  Is this a known bug?

Version: 6.0.1
Build id: 20050725_1800

Thanks in advance for any help anyone can provide.
--Bruce Guetzkow