found playville..no problems playing.. i ploughed and stuff and then they said come back tomorrow to harvest, maybe played for 10 mins..no freezes and memory usage is normal..it's not a heavy flash game, don't know why it's causing you problems..do you have the same freeze with other browsers?
also check the max script run time..in kmeleon go to about:config
(edit>configuration)
filter the search by 'script
look for that pref:
dom.max_script_runtime
double click on it and fiddle with it..increase the value
restart kmeleon(remeber to restart the loader as well so the pref is saved)
test again with facebook
hope this works