I'm on a lap top too at the moment and using Firefox. If you hold the control button down and tap the plus sign, does that make a difference in what you see? It makes things bigger and more spread out on the screen for me and I don't feel like spacing is as much of an issue. Forgive me if that isn't the problem you're describing.

My default zoom is 100%.
Right now I have the font set at 12 point and the line spacing is better, but that font that small is hard for me to read. I'm going to try it on various DU pages and with various zooms.

Bookmarking this thread for solutions. You can't be the only one experiencing this.

Have to hit ctrl-0 (back to default zoom) for any page with lots of titles / headlines.

At 150%, columns disappear.

I now have Firefox set to NOT "Allow pages to choose their own fonts".

that might be interfering such as text enhancements?