psanningsync open triggers apple message

[cnewhall]

every time i open spannigsync, whether on startup or from the pref menu, i get the message "this is an application downloaded from the internet. are you sure you want to open it.?  etc....)   i do not get this mesage repeatedly with other programs downloaded from the internet, but only the first time and never thereafter.  what is the problem that is causing this behavior.