Hmm..strange indeed. I opened a NPB case this morning with no problems.
I checked there Announcements and got this:
***Scheduled Maintenance For This Week***
August 15, 2012 | 08:55AM PST/PT
The eBay system will be undergoing general maintenance from approximately 23:00 PT (11pm) on Thursday, August 16th to 01:00 PT (1am) on Friday, August 17th. During this maintenance period, certain eBay site features may be intermittently unavailable or slow.
But I wouldn't think they would still be undergoing maintenance because it was only through Friday. It could just be something quirky going on due to whatever they did. I would try again tomorrow morning and if it is still acting up, I would call ebay.