Access is denied crawl SharePoint 2007 webapplications

If you're using host headers when creating new webapplications in SharePoint, you'll probably get this error when you're trying to run the search crawler:

"Access is denied. Verify that either the Default Content Access Account has access to this repository, or add a crawl rule to crawl this repository. If the repository being crawled is a SharePoint repository, verify that the account you are using has "Full Read" permissions on the SharePoint Web Application being crawled. (The item was deleted because it was either not found or the crawler was denied access to it.)"

To fix this you can create the webapplications without hostheaders or you can try this:
http://support.microsoft.com/kb/896861

I've used the first method:
- run regedit
- goto HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0
- add a new Multi-String Value named BackConnectionHostNames and press enter
- edit the new key and type the host headers you would like (seperate by newline)
- exit regedit and restart the IISAdmin service

More details can be found at Tommy Segoros blog.