I have a Imac 400(running panther 10.3.5) that came with 1 stick of apple ram(64mb) marked PC100-222-620. The other stick that came with it was a kingston 512 marked KTA-IMAC100/512. Will my Infineon 512 stick that is marked PC133-333-520 work well with the slower ram? I was told different things about this. When using both 512 sticks everything seemed ok. I just don't want to mess things up. Also. Do I need to do a firmware update when running Panther on this imac400? I did try to do the update but I was getting an error message about not being able to find the OS9 folder. Thanks for any help.