translucency and two-sided problem?

[Image]http://img767.ph.126.net/079dY8kanb5KyXxW-hoaSA==/1211186824786973922.jpg[/Image]
[Image]http://img767.ph.126.net/5QqgU7R6gDskAuWZcH0Y3Q==/1211186824786973925.jpg[/Image]
[Image]http://img610.ph.126.net/2o5yvCyx9BqwcuBmLZlpMQ==/1688286910312032300.jpg[/Image]

I have made a box that has a alpha channel in png,and set the 2 sided enable in 3DMax 2008 with the DTS explorer,after i put it into the game scene,that has a problem that at some direction look right but at other side that some face disppeared.And the material code is below：
new Material(SimpleTexture4)
{
mapTo = "SimpleTexture";
baseTex[0] = "SimpleTexture";
translucent[0] = true;
translucentZWrite[0] = true;

};
Who could point out the problem?Thnx:)