Hi!
I, too, had faced this bottleneck. But, as eBay advises, it is only temporary, while I presume it could be linked to any bidding/buying or selling over and above any of your previously unresolved transactions (e.g., unpaid items). But once you register as a seller (look up Help) or continue to bid for your current item, you will be directed to a page where you can choose to become verified or upgraded for an 'unlimited' amount by (i) an SMS from your mobile phone to eBay or (ii) online cross-checking of your credit or debit card details, or (iii) postal confirmation by a security code sent to you by eBay. I hope this answers your concern.
