Checksum error at bootup

[Jesse W. Asher]

I've had this happen to me a couple of times so I thought I'd better find
out what's causing it.  I've got a Sparcstaton 1+ running 4.1 and a couple
of times when I've tried to boot the system from the PROM monitor prompt,
I've gotten an error message like: 
        checksun xxxxxxxxx != xxxxxxxxxx 
        Trying to boot anyway.

At least one time after I got this message, I then got a "memory out of
alignment" or some such error and it refused to boot.  I've had to
reinstall everything each time after this has happened and, frankly, I'm
getting a little frustrated with the frequency of this happening.  Can
anyone tell me why this is happening, what I can do to avoid it, and what
I can do so I don't have to reinstall everytime?  Thanx for any help for
this poor, wretched, Sun-ignorant soul.  

         Jesse W. Asher                             Phone: (901)386-5061
                       UUCP: ...!banana!hbmc!jessea