Another, this time very scary, letter from the ATO about past due BAS forms. Huh? I filed those! They're paid for and everything.
Rung the ATO at about 11:30 today and spoke to "Jane", apparently it looks like the computer system didn't finalize them until the 11th, and the letter went out the 10th (presumably a follow-up to the original letter, and I couldn't react in a timely fashion becasue of aforementioned ATO website breakage).
Hopefully this is the last I hear from them.