Page in Frames keeps jumping back

I have created a website and used frames to show a gallery of pics which when
clicked image in the middle frame changes...the prob I'm having is in the
bottom frame (gallery), when it is scrolled along and a pic is clicked it then
jumps back to the beginning of the gallery (page). This only happens on a
pc...on a mac it works fine and the gallery stays wher you last clicked.

Does anyone knmow of a solution to this problem?