Just installed Maverick and iBook going crazy

Hello.

I just installed Maverick and I keep getting this message from iBook:

Sign in to download from the iBooks Store.

If you have an Apple ID and password, enter them here. If you've

used the iTunes Store or iCloud, for example, you have an Apple

ID.

Create Apple ID Cancel Sign In

Whenever I click on Sign In it does nothing and the message pops back up. Also when I click on Cancel, same thing -- it doesn't cancel.

Additionally the Create Apple ID does nothing.

Any ideas?

Thanks.

Regards,

Phil