Okay, so what? SSL connections are secure, encrypted communications between your browser and a remote website - like, say, your bank, as you're reviewing your account balance. They're secured so that nobody can intercept them while in transit, and gather your account number, password, etc., and make trouble for you later. Part of that security is not storing information from that secure connection locally, so that nobody can bypass the encryption by getting into your machine and reading the info from the disk cache. Mainly, this will be a problem when you (someday) dispose of the computer - unless you take steps to securely wipe the disks, whoever gets hold of it could potentially read all kinds of interesting things about you.
Anyway, realistically speaking, there isn't a heck of a lot you can really do to speed up dial-up connections - the bottleneck is the phone line, not the browser, so tweaking the browser won't do much for you. It might make it feel faster in some cases, but it's not going to actually make it faster.