adverbs of frequency, word order

[Lenka]

Why does the adverb "usually" not stand between "don't" and "count"?

Footnotes usually don't count in the number of words in an assignment.

(from: http://www.usingenglish.com/members/tests/ - the first test - Academic English)

[Tdol]

Why not? It can go before the negative as well.

[Lenka]

Why not? It can go before the negative as well.

It CAN go or HAS TO go before a negative verb?

[Tdol]

The normal word order would be after 'don't'. There's a very slight shift in meaning, I think; by moving it before the negative, the negative points more at the verb than the adverb. However, it's so slight that I find it hard to explain.

[Lenka]

OK, thank you :)