Which scala version is used? Contradictory information reported at command line.

I edited `project/Build.scala`, setting `Keys.scalaVersion := "2.10.1"` . Now when I fire up `play`, it still tells me it is `using ... Scala 2.10.0`, but then `scala-version` will report `2.10.1`. What is the meaning of this?

```
$play
[info] blahblah
       _            _
 _ __ | | __ _ _  _| |
| '_ \| |/ _' | || |_|
|  __/|_|\____|\__ (_)
|_|            |__/

play! 2.1.0 (using Java 1.6.0_43 and Scala 2.10.0), http://www.playframework.org

> Type "help play" or "license" for more information.
> Type "exit" or use Ctrl+D to leave this console.

[dev_portal] $ scala-version
[info] 2.10.1
```