flash crashes are rarely if ever caused by the browser itself. the games might require higher pc specs..check for minimum requirements and flash version.
try to test by installing the standalone flash plugin available there:
http://kmext.sourceforge.net/mplug.htm
extract the zip directly in k-meleon\plugins\ folder so npswf32.dll is saved there
restart the browser and test those flash games.
what are your pc specs and os?