AVR-Chat

> This is typically symptomatic of using uninitialized variables (in C -
> in assembler it would correspond to uninitialized registers).

Yup, or stack pointer corruption, or a jump out of a routine due to
copy and paste problems, (jumping into the old routine instead of
within the new one)

> There's also the whole byte/word difference problem . (i.e. you're not
> trying to erase the area that the bootloader is in when you really
> think you're only around the 64k mark).

Actually, one of the first things the code does, is set the protection bits.
And I'm sending out on a diag pin, the RAMPZ and Z registers while I'm
writing, and they are always sane.  $000000 through $01FD80 . The "80"
is because I would have just finished writing the second packet into
the spm buffer, and I started the write with the pointer there.

I know I need words, not bytes.