I haven't required any support from Microsoft ever. I notice that they had to buy another company to try to prevent their current OS from being infected/corrupted, so I suspect they aren't too well informed about the activities of their in-house coders.
98 re-calibrates it's cache fairly frequently unless you tell it not to. Just go into virtual memory and set it to a fixed size.
HS - a few things about Norton make you suspect that they are not too stessed about people getting infected - it probably means they can sell them a bit more stuff or an upgrade.