It's that old prob again with the KM1.5 gecko engine getting outdated by now, so more and more pages with modern layout commands show display errors.
All looks fine in KM1.6beta. It's quite usable really, you can try it parallel to KM154 if you want. There are some minor flaws yet, but concerning mostly the browser handling itself, while page display is definitely better than in KM154. Many of us here already use 1.6beta2 happily for daily use, but additionally have picked up some more interim fixes in the forum. We hope that soon a beta3 will appear with those fixes already included, that would be an important step forward.
If you still use KM154, there are some fixes out there via CSS modifications, but those only work on a per-site basis, and it takes some savvy person to figure out the needed code.
At any rate take a closer look here:
http://kmeleonbrowser.org/forum/read.php?1,115782