Testing site migration before DNS changes…

I’m in the process of migrating a WP blog to a new hosting plan but I don’t want any downtime. I’ve been using the basic instructions from this page. So, to assure the site is working correctly before I go in and change the DNS settings for the domain, I figured I’d to some testing of the site myself. To do this, I added a line to my hosts file (found in C:\WINDOWS\system32\drivers\etc) to point to my new hosting plan by IP address. This way, I could test the site using the same domain name (and, if there were any URL-based tags in the database, it should work just fine for my machine). Anyways, this seemed to work until just after I did a fresh install of WP. Now, when I try and view the site, I get prompted to download a file (a text/vnd.wap.wml file) and I can’t view the site outside of the WP control panel…

Any ideas?