How to prevent a System.Timers.Timer (Server timer) from getting killed or Prevent it from garbage collection

Question

Can any one tell me how to prevent a server timer from getting killed on the server or from garbage collection. ACTUAL PROBLEM: I am using this server timer for a scheduling module which will run through my database tables and do some useful work. I have set "Autoreset=true" so that it repeats itself. Now the problem is from some days the timer is getting killed automatically on the server(Previously i used to kill it manually when the elapsed event occured). can any one tell me what the problem could be