[lug] error -2147483630 reading header:

[Kevin]

>>>>> "matthew" == matthew w mcillece <matthew.w.mcillece at lmco.com> writes:

matthew> ...strange tale of install woe...

matthew> Does anyone have any insight into this problem?

well, that error is coming from 
/misc/src/anaconda/isys/uncpio.c

        if ((rc = getNextHeader(&fd, &ch))) {
            fprintf(stderr, _("error %d reading header: %s\n"), rc, strerror(errno));
            return CPIOERR_BAD_HEADER;
        }

It's apparently happening from the loader. The loaders job is to load
the installer into memory and run it. 

Could it possibly be that the heatsink is touching or interfereing
with the memory? You might try running xmemtest86 on it (can't hurt). 
http://reality.sgi.com/cbrady_denver/memtest86/

Also, does the processor have an external cache? might try disabling
that in the bios. 

Other than that it sounds like the cpu is somehow really flaky...

matthew> -Matt

kevin