Blank addresses on OE on Mac

I’m running Outlook Express on a Mac OS 9.2.2.
It seems to have the address book messed up. When I start a new e-mail and start putting in a recpreient, the address auto fill brings up a list of addresses that match the reciprient’s name. For instance, if I type in Mike, all Mike’s should be listed in the drop down menu from which I can choose one.

What happens is that some of the items listed in the drop down menu are just blank lines. I know there’s no blank address in my address book.Is there anyway to ‘fix’ the address book?

Thanks