Removing thumbnails

Hi all,
here again, I use one of the Kirupa tutorial for my site. I added thumbnails to my photo galleries based on the tuto:

Everything works fine except one thing. The thumbnails are isolated into their own MovieClip and then I switch between galleries re-using this MC…good.

But consider I visit the first gallery which contains 5 photos, when I switch to the 2nd gallery which contains only 2 photos, 5 thumbnails are displayed, the 2 first ones from the current gallery (the 2nd one) and the 3 others are form the first gallery.

Each time I switch I tried to clear/unload/remove… the movie clips involved in my scroller but without any success.

Any idea? Thanks a lot in advance.