Opera advice needed!

Hello, I just noticed when I published a new menu system that it does NOT work in the ISP hosted server. However it works ok on my test server. Here's the test I have done all in same client machine (=unchanged browser settings): My test server: IE6 & 7 ->OK Opera 9.02 -> OK Firefox ->OK ISP server: IE6 & 7 ->OK Opera 9.02 -> DOES NOT WORK! Firefox ->OK The system relies on JS also I can see from the browser source code that all PHP has printed out all JS like it should but the menu is not printed to browser. Could you give me some pointers how to troubleshoot this? It must be something server related but not folder or file rights according to my testing. Thanks -Will