About Upgreading to New Verison 5.0 --> 5.1

[Vahric MUHTARYAN]

Hi Everybody , 

	I want to try How can I upgread FreeBSD 5.0 to 5.1 but I'm
getting panic I don't understand why ?!  

Error Message is ; 

Panic : page fault 
Syncing disks , buffer remaining 

Fatal trep12: page fault while in kernel mode 
Fault virtual address = 0x1c
Fault code = supervisor write pager not present 
Instruction pointer : 0x8:0xc02fb3c5
Stack Poinrer = 
Frame Pointer = 
Code segment = base 0x0, limit 0xffffff , type 0x16 
		 = DPL 0 , pres1 , def321 , gren 1
Processor Eflogs = interrupt enabled , resume , IOR=0
Current Process = 9 (bufdaemon )
Tramp number = 12 

Panic : page fault 

Thanks ...
Vahric