I've been using Vector with no problems in Flash Builder Beta, but when I try the same thing in Flex Builder 3, the compiler throws a fit when I use it.
public function PuzzleEvent(type:String, pieces:Vector.<Sprite>, bubbles:Boolean=false, cancelable:Boolean=false)
The other strange thing is, Flex automatically adds this line when I use vector:
An import shouldn't be necessary should it? Vector is in the top level package right? With or without that import statement, I get compile errors. Has anyone else had such problems with vector in Flex Builder?
Vector came in with Flash Player 10 - as targeted by Flash Builder 4. Flex 3 targets player 9, hence your problem.
You need to change your compiler settings to target FP 10.0.0. Vectors and other goodies exist only in FP10. If your project targets any earlier version those features are not available.
The only way I was ever able to solve this problem was to use Flex builder Beta and now Flash Builder 4. I did target flash player 10.0.0, but I still never could get it to work. At least it works in Flash Builder 4.