Global robots.txt for multisite blogs

Hi all,

We manage different clients under a single multisite install. We’ve started using time.ly for a few different clients, and have noticed that the automatically added robots.txt entries are global. You can see an example here: http://www.encomputers.com/robots.txt

There you can see the “Disallow” line for three different websites, when it should only be one.

Is there any known way around this?

Thank you!