Can't display a chart again after closing original display window

``` fsharp
#load "../packages/FSharp.Charting.0.90.12/FSharp.Charting.fsx"

open FSharp.Charting

let chart =
[1..10]
|> List.map (fun n -> (n, n))
|> Chart.Line ;;
```

This displays the chart, as expected. Now close that display window, and try to display the chart again:

``` fsharp
chart ;;
```

Result:

```
val it : ChartTypes.GenericChart =
Error: Exception has been thrown by the target of an invocation.
```