My school has ~15 iBook G3's(600 MHZ, 128 MB RAM, OS X 10.2.8) that are suddenly unable to hold the date or time. They are plugged in constantly, batteries in, and are always on. I know that with the Pismos, there are PRAM batteries that you can replace, but if I read Apple's support pages right, there aren't any in the iBooks. How does this happen? How easy is the fix? TIA. I appreciate it.