ClassFormatError: Illegal class modifiers in class ... 0x209

I have a few some strange issues with my class after migrating from JDK5/Tomcat5 to JDK6/Tomcat7 both with MyEclipse 9.

Whenever I try to access 'myclass' via jsp:usebean I got following error

org.apache.jasper.JasperException: javax.servlet.ServletException: java.lang.ClassFormatError: Illegal class modifiers in class myclass: 0x209

The rest of log points nowhere. By trial and error I have trimmed huge class to the following problematic part:

 ...
 rf = store.getDefaultFolder();
 f = (IMAPFolder)rf;  
 final IMAPStore storeNew = store;
 Ob开发者_如何学编程ject val = f.doCommand(new IMAPFolder.ProtocolCommand() { <-- problem propably starts here
 public Object doCommand(IMAPProtocol p)
throws ProtocolException {
 ...

The next strange thing is that my colleague is using the same environment with no problems. I have compared our class files and the only difference is in last but one byte. My class ends with '02 09', his '06 09'

After several days I am out of options how to get rid of it.

EDIT:

I have reinstalled/updated to MyEclipse 9.1. No luck so far.

SOLUTION

After another day trying to reproduce problem with a new project with a single file in it, I have realised that only remaining difference is in project/properties/java build path/libraries. There was J2EE 1.4 Libraries in the main project, so I have replaced it. After adding Java EE 6 Libraries voila. I am able to compile and run w/o any problems