VirtualSite, the PKRAM "chord" indeed resets the parameter RAM (I have just confused it with a tool...) which is not recommended to be done frequently. There is also no problem with memory sectors. There is a very small number of third party hardware parts that might use some bits in it, and if you reset it you might even cause problems. So my general advice would be: Don't touch it, unless your Mac shows hardcore problems, like permanent mouse freezing, immediate startup crashes or uncontrollable permanent re-booting - that sort of thing. It's the final thing you could/should do yourself before you bring it to the repair folks. OS 9.1 seems to be a bit unstable in its general behaviour and clashes with a couple of system extensions - AdobeATM among the list. It was a bugfix release for OS-X (where it seems to run a bit better) but caused new problems without OS-X. OS 9.2 is said to fix both worlds, but I did not test it yet.