Lightstreamer can listen on any port but we advice to use standard ports for two main reasons:
  • this issue with Opera browser
  • you may have some users behind a proxy that are unable to reach non-standard ports.

Btw the problem you're facing is related to the configuration of the demo pages: check the HOW_TO_DEPLOY_ON_YOUR_WEB_SERVER.TXT file under LS_HOME/pages/demos for a solution

Let me know if you have any problem with that.

HTH