The screenshot below is what I see using Firefox and the Userstyles CNN script. No popups or new tabs/windows. Does it look the same as yours or is anything missing?
Did you paste the full code, including the final
} ?
In Firefox's Options, click the Content tab. Make sure 'Block popup windows' is enabled.
I use the NoScript addon to block unwanted ads, scripts, flash, java, etc. When I click its icon for the CNN page there's a list of addresses that can be blocked - cnn.com, turner.com and advertising.com. This last address is the one generating the ads, so add it to your Blocksites list, although I would have thought your NoScript would be blocking it anyway.
