Yes they should, they've worked fine on my Indigio 350 iMac and my Graphite SE 466Mhz iBook which has the same graphic's card as your iBook.
Just make a backup of your current ATI & OpenGL drivers (i.e Duplicate them, do NOT simply move them from the extensions folder to a new folder, you must leave your original drivers where they are, in your extensions folder) and then drop these new ATI/OpenGL extensions on your system folder, or place then in the extensions folder in your system folder, you will be asked if you would like to replace your current extensions/drivers with the ones your installing, click yes.
I repeat do not DELETE your current ATI/OpenGL extensions and THEN install these new ones, you must drop your new extensions/drivers on the system or extensions folder and let the Mac OS replace/update them for you, or you might run into loads of probs (as I did).
Also I "think" these drivers only update 3D performance, so you would not want to delete your 2D extensions.
Good luck, they should work fine.
[ 08-18-2001: Message edited by: roders ]