tomcat stop running

hiya!!!
Im assigned to a website where jsp,mysql, and tomcat is used which runs on fedora 5. NOw i wonder why sometimes the tomcat will stop running, so i have to restart it again to keep the website up and running. BUt that's not only the problem because sometimes even if i already restarted the tomcat, nothing happens, so i restarted the computer to make it work..
Can anybody help me trace where the problem is?? OR can anybody give me all the possible reason why tomcat will stop???
tnx... i really need your answer guyz...

re: tomcat stop running

maybe you dont get exactly what i mean.. We have a CMS editor and programmer at the different location. I understand that when you add or edit something in class you have to restart tomcat but sometimes i dont know why tomcat still wont run even if i restarted it already... And when i reboot the computer it will run again.. what's the difference of restarting tomcat and computer when in fact only tomcat that matters?? pls.. Its been a while thinking about this problem... can anybody give me some piece of solution or suggestions?