So why did this guy just target Democrats and liberal media, enemies of the Bush admin? Why did he associate it with 9/11, attempting to pin it on Islamists? How was he able to get everything ready in a week? How was silicon use to weaponize the anthrax when Ivins didn't have access to the tools to do this?

Killing oneself with Tylenol seems as odd a decision as David Kelly's "suicide" by penknife. Also no suicide note, yet they didn't do an autopsy.

Statistically, suicide notes are very rare--their absence is something to be expected, not suspicious of.

It is odd that the sender was smart enough to make the return address "4th grade" at some school, but was not smart enough to spell penicillin correctly.

Maybe he wanted to throw people off his trail by misspelling a word a doctor would be able to spell correctly.

Could you imagine how terrible it would have been if he misspelled the to: address and it was returned to sender(assuming that address is legit)?

In the full report -- as referenced by previous item <http://news.ycombinator.com/item?id=1138099>; -- it's suggested the misspelling was intentional to highlight a code of bolded 'T' and 'A' characters.