I am using externalized config section for appsettings, to be able to have different ones per developer, like so:

```
  <appSettings configSource="appsettings.config" />

```

When I run mstest against this project (it's a web application), it blindly modifies this section like so:

```
  <appSettings configSource="appsettings.config">
    <add key="microsoft.visualstudio.teamsystems.backupinfo" value="1;web.config.backup.af6ed449-e04a-4a52-99d6-b8df0b133316" />
    <add key="microsoft.visualstudio.teamsystems.aspnetdevserver:/" value="56917;True;3448;1;-8588944684513929784" />
  </appSettings>

```

Which is obviously wrong, even according to schema. 

The reason it needs to modify this is to specify the information about Cassini/dev server that it's going to run. I think that's it, it doesn't seem to modify any other section in the file (very hard to tell since it also completely reformats the file).

Question is, what choices do I have to get this to work? 

So far I only came up with two practical ones, both sub-optimal

1. Abandon external config for appsettings
2. Switch from Cassini to cassinidev - then I can stop using
[AspNetDevelopmentServer()]
attribute, which is the one that
results in web.config needing to be
modified
3. Configure something in VS to prevent it from doing this. Why does
it even care which port its own
cassini is working on? I couldn't
find any config settings.
4. Wait for MS to fix this, so [AspNetDevelopmentServer()] would
work with externalized appSettings