I'd go to a local Wamu branch and discuss it with them first to see what the deal is. Don't call them, as their phone reps are very uneducated, and mostly say "I'm sorry for the inconvenience". And their escalations dept. (aka 'supervisors') aren't any more helpful.
Because you actually applied for and received a biz CC, it won't do any good to contest the second inquiry (I've tried before with TU, and all you can do is declare fraud, which would be a bogus claim anyway).
The local branch manager might be able to help... they did with me.
