The following has just worked fine for me for installing Macromedia Flash 7 plugin:
Go to the Macromedia Flash website at http://www.macromedia.com/software/flashplayer/
Follow the Get Flash Player link, then click on the Download Now button, to download the file flashplayer7installer.exe (644 kB). Double-click that file when downloaded and it auto-detects your browsers: including K-Meleon!
Installation complete :)