suid application

I run an application called filePro. It runs suid filepro ( perm 4755 owned filepro, group user ). It was developed on RedHat 6.0 straight out of the box. In SCO Unix and ( according to the developers in RedHat ) if you use the shell command feature within filePro to do a system command such as 'cp file file', it operates as user filePro. In SCO this is true for sure. In SuSE 6.4 and 7.0 this is not true. The created files carry the name of the original user. Other commands in filePro that create files have the filePro as the owner. Why would the shell command not? Is there some security setting in the kernel? Greg Engel