I have had the same issue, everytime I run a xml file through blogger2wordpress, I get a mixed bag of posts from several authors... and many of the posts I'm looking for vanish.
So as far as I can see, there is currently no viable option for importing a blogger blog into wordpress.
I don't even have a lot of posts to manage here, just 250 posts, without comments. There are a ton of embedded flash movies, as well as uploaded images.
I've tried authorizing blogger to share info with wordpress on my own server, and receive no posts, no nothing. it just doesn't do anything.
I've tried converting from ftp to blogspot, then importing from a blogspot blog into a wordpress.com hosted blog, and I lose all attachments, even if I opt to download them.
I've tried uploading the blogger xml file to a wordpress.com blog, and lose attachments.
I've tried downloading the blogger xml, and running it through blogger2wordpress several times. Each time I get multiple blogs of content, but not all of my own... it DOES keep SOME of the attachments though.
With blogger's deadline looming, this is a serious issue. I really hope someone from wordpress notices this issue and supplies a working fix. For instance, why can't I choose to upload the blogger xml file directly to my own server, the way I can on the wordpress.com hosted site? How can I keep the attachments?