you might have installed 1.5 on top of 1.1.6(dirty install)..this will cause all sorts of problems due to incompatible kplugins.(especially with layers plugin..it will crash you)
also if you've installed 1.5 to use previous 1.1.6 profile..this will even cause more trouble.
first locate your profile folder(in km click on edit menu>configuration>profile directory)
backup your profile directory.
close kmeleon..delete the old profile or rename it.. just to make sure 1.5.2 won't use the same profile.
now go to k-meleon's folder and rename it as well as a backup
for example, if it's called k-meleon rename to k-meleon116 or kmeleon-old
this way new kmeleon won't install on top of the old folder
now install latest 1.5.2
it should create a new folder with a new profile and all the problems will be gone i assure you.
once you're satisfied everything is working as it should, you can start customising your new 1.5.2 and import your bookmarks from the older profile.
i hope this helps and good luck.
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