Tools-Browsing Options-Layers Only or Tools-Advanced Preferences-BLOCK sites from altering browser settings sets that pref to 'true', but it still failed the test when I tried it.
Loaded the new exe and kplugins, and went testing.
Clicking on links in the page resulted in the page not being rendered, either in the same window or in a new windows/layer.
Rolled the exe back to a November build and all is well again.
I tried this on numerous sites, including my banking page, and had a 95% failure rate.
Seems something went wrong in the coding.
It isn't possible to use the current beta for day to day surfing, it's broken a bit too much. I don't know what Ulf tried, but selecting text and all key accels break after a few minutes of surfing (and opening and closing some windows) and K-M just displayed the text I typed in from right to left(!) (so, the word "K-Meleon" looked like "noeleM-K" - was that a try on Chinese or UTF-8 support?). K-M's process keeps on running after closing the final window in like 9 out of 10 times.