[R] box() and hist()

[garbade@mip.paed.uni-muenchen.de]

Hi,
does anybody know why the following is not working:

> hist(rnorm(200))
> box(bty="o")

gives me a box without rounded corners.

System:
> R.Version()
$platform
[1] "i386-pc-mingw32"

$arch
[1] "i386"

$os
[1] "mingw32"

$system
[1] "i386, mingw32"

$status
[1] ""

$major
[1] "2"

$minor
[1] "0.0"

$year
[1] "2004"

$month
[1] "10"

$day
[1] "04"

$language
[1] "R"

Thanks, Sven