Building from the Expando IQuackFu example here:
http://svn.boo.codehaus.org/trunk/tests/testcases/integration/duck-5.boo?view=auto

This code gives an error at the first named argument:

point as duck = Expando(datum:2,squared:2*2,coord:5)
print point.datum, point.squared, point.coord

#should work the same as this:

1. point as duck = Expando()
2. point.datum = 2
3. point.squared = 2*2
4. point.coord = 5
5. print point.datum, point.squared, point.coord

With regular classes this works fine:
class TestClass:
public datum as int
public squared as int
public coord as int

point as duck = TestClass(datum:2,squared:2*2,coord:5)
print point.datum, point.squared, point.coord