Unlike PhotoShop versions I use at

Unlike PhotoShop versions I use at work now (CS2), and in the past, my Adobe CS3 loaded onto my personal Macbook Pro (v 10.4.11 - 2.33 GhZ Intel Core 2 Duo, 2 GB 667 MhZ DDR2 SDRAM) is not allowing me access to special effects filters for enhancing some art I have recently designed in the same app. I went to Preferences menu and located a dialog box which appeared to be a launch for accessing the effects filters. I was interested in applying brush stroke or texture to my art. There was a live blank box for entering the Serial No of my CS3 Suite. You'd think that the requested serial no. that was printed on the sticker on the back of the DVD jacket would be what I needed, but not. I was given a message that I had entered the incorrect serial no. Can someone answer either or both of these dilemmas? Many thanks! Bob