JBulider2006+JDK5.0 建com包然后做swing界面不能切换到design模式
报错内容：
Invalid index processing BeanInfo class com.Untitled1BeanInfo
class sun.misc.InvalidJarIndexException Invalid index
Unable to design Untitled1.java. Make sure that the file is in the current project, does not contain any syntax errors, and that all resources are compiled.
这是因为在JBulider2006中，com被认为是默认包，设计时包名不叫com时就没问题了。