I just installed 10.6.8 and have the same issue. It appears 10.6.8 broke Safari. I hate cookies, and always have Safari set to "never". If ad companies want to pay me to track my web use, that's one thing, but I'm certainly not going to let them do it for free! I'm quite frustrated this slipped through Apple's QA, and hopefully they will fix this soon. In the meantime, FireFox works fine. I normally use Safari for general browsing, and FireFox for the occaisonal site I need cookies for (and I have FireFox set to clear all information upon closing). If you do banking online, you certainly don't want cookies laying around on your machine. Unrelated, it's important to delete Flash cookies, which most people don't do. These are buried in user/library/preferences/macromedia
You need to lock the "#SharedObjects" folder (press command+I on the folder and click "lock"). Then also click throguh the "macromedia.com" folder to "sys" and lock that folder. A few sites will require you to unlock the "#SharedObjects" folder to play their flash video, but most don't require this. I dropped the Flash folder in my "places" section so I can quickly access it when needed. Flash is evil stuff, no getting around it.
It would be nice if our web browsers could block Flash cookies as well. At any rate, Apple should fix this Safari cookie issue ASAP!