problems importing content

someone that had the password to access my host deleted some information and my blog was unable to be seen. i had no previous backups, but i could access all my posts when logging in.

i did two things:
1. i created a back up file in my host with all the files that were there at that moment,
2. i exported all my content using the export tool in WP.

the problem is now, when i import the XML file, it doesn’t work. it gives me several errors, and all i see in the blog is the first post ever.
i suspect that all my posts should be in that backup i created after the problem. if at that time i could edit all the posts in my dashboard, the information was there. how can i put that back on?

it would be great if you could help me.

oscar