Fedora 3.0 kernal panic

After a few days of operation (my Linux box is a Sendmail mail server) the system kernel panics comes with information about stack pointer is garbage , BAD EIP Value, Fatal Exception in interrupt ,not syncing : Why is it causing my system to kernel panic? . I have DELL Power Edge Sever 2580 (prevoiously I thought that it may be the problem of RAM then I changed the Harware itself and Put 4GB of RAM in new DELL Server) SWAP Space is double of RAM and Put new kernel 2.6.12. Butt Still the Problem is exist. pls help me