[pstricks] Help! Can not place labels on arcs.

[Deling Ren]

Hi, all,
I'm using PStricks with MikTex on Windows. Everything else seem fine, but when I try to place a label on the node connection arc, it just do not work. Instead of attaching the arc, the label is just placed after the picture. What's more, all labels were place at the some position, overlapping. The following is my source:

\begin{center} \psset{unit=1cm}
\rnode{1}{Node 1}
\vspace{3cm}\\
\rnode{2}{Node 3}
\ncline{1}{2}\Bput{Label}
\end{center} \vspace{1cm}

Does anybody have an ideal what's going on? Thank you very much.
BTW, I installed PSTricks package by copying everything under Local TexMF\latex directory, is that the right way?

DelingGet more from the Web.  FREE MSN Explorer download : http://explorer.msn.com
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