I have found these bugs in K-Meleon 1.6.0a3 (Build 4, 2010-03-01, Gecko 1.9.1)
Under Macro Extensions
I unchecked Zoom, NewsFox, Mail and IE and restarted K-Meleon but it failed to start.
It showed an error
Therefore, I had to delete all K-Meleon folders in User Folder and reinstall for it to work again
It seems to be the combination of mail and zoom being set to false which causes the problem. I did Zoom, NewsFox, Mail and IE one at a time and then in combination. The failure to start was with Zoom and Mail.