Creating FP Users - or maybe- does Cpanel use MS-FP code for creation

I am trying to add an additional FP user/author (an addition beyond the root/default user created by the WHM "Install FP Extensions").

When I go through the MS-FP process that is done from Front Page (Tools -> Server -> Admin Home -> Add a user), I received the following message from the server extensions tool: "The password file
"/home/xx/public_html/_vti_pvt/service.pwd" was not created by this client program and cannot be edited safely using this client program."

Is there any other way, work around, etc to add a user to the FP list of authorized users? I can't find anything in cpanel/WHM that will do this... are we limited to one MS-FP user per domain with cpanel ? Or is there some other way to accomplish this on Apache 3?

Thanks,