Firefox which stops responding after some time is a BIG problem. You're not the only one. The problem seems to be with sites which require Java. The problems I seem to have spotted is this : You visit a web site which needs Java so Java asks Firefox for the amount of memory needed and this is lent to JAVA. However, when you leave that web site, Java is naughty in that it doesn't give back the memory borrowd. Firefox then has to consume a lot of memory to the point that the whole computer system grinds to a halt as you have run out of memory. Search in the forums for high memory or RAM and you will see many threads. In fact, when you first install Firefox it will ask if you want to send anonymous data about the memory usage!!