I am using a WP 3.0.1 Multisite network using subdirectories. This works pretty well, but there is a issue left that is pretty important for me:
The subdirectory blogs do not output a robots.txt. This is no problem when using them as subdirectories, since only the root robots.txt is used.
But in combination with the domain mapping plugin this becomes an issue, because the mapped domains do not have a robots.txt.
I tried this with a multisite setup using subdomains, there robots.txt files are created when looking for them on the mapped domains. But I can't use this setup productively at my hoster.
Any ideas how to fix this?