It is a limitation that happens very frequently.
eBay is letting you sell the products but not sending the money...
I would recommend sending the document as soon as possible and suspending sales...
If your account is secretive, stop everything and try to send a false document (this can block the account and get your money in 3 months, or they accept it and you continue receiving the money)
Well, they froze my funds. The account is fine and is able to keep selling, but they money is kept by ebay until I submit my tax id number. So, there's that...
UPDATE: They released the money to my bank account, but the selling privilleges have been revoked.