I have done this about 8 times now.
Step by step process:
1) Use tumblr2wordpress
2) Clean up XML file
3) Upload to WordPress.COM
4) Clean up titles
5) Export from WordPress.COM
6) Import to wordpress.ORG
At this point it usually says one or two of the posts didn't upload.
I then go to see, and sure enough several posts are missing. However the bigger problem is that when I go to create a new post, instead of a "Publish" button, I get a "Submit for review" button. This "Submit for Review" button doesn't even work. I also can't move any of the posts to the trash.
I have checked and I am still number 1 admin.
I've looked through several support topics similar to this, but can't seem to find the answer. Every time I do the steps above I end up having to delete WP and start from scratch. I really need help with this urgently