user-guide changelog syntax error

[eluser]TWP Marketing[/eluser]
This does not parse in english:
Page: http://ellislab.com/codeigniter/user-gui...gelog.html
Topic: General Changes

Line: "Fixed a bug where Email library attachments with a "." in the name would using invalid MIME-types."

I assume there is a missing verb or adverb toward the end of that sentence, before the fourth word from the end of the sentence. Perhaps "be" is the intended word?