Tested JRE: b130-pit http://rehudson.sfbay.sun.com/hudsonws/deploypit/bundles/ Label: b255-2011-02-10_39
Tested OS: winxp
Tested Browser: firefox3.6, IE8


Steps to reproduce:
1) Launch the following applet in browser
http://rehte.cn.oracle.com:8080/wshost/new_ws/deployment/src/plugin/Decoration/Decoration/html/DecorationInvalidParam.html
or http://sqeweb.sfbay.sun.com/jsn/users/fred/master_run/deployment/src/plugin/Decoration/Decoration/html/DecorationInvalidParam.html

its decorated parameter's value is abcd, which is invalid.
2) Drag it out of browser

3) If the frame is decorated, bug is reproduced. dragged non jnlp applet should have undecorated frame like it behave default.
 

Source code location
http://rehte.cn.oracle.com:8080/wshost/new_ws/deployment/src/plugin/Decoration/Decoration/src