iBoku uses advanced web 2.0 capabilities. In order for your browser to support these capabilities, you will need to upgrade your browser with the Google Chrome Frame plugin.
The upgrade only takes a few seconds, doesn't require a restart, doesn't contain any malware (it's from Google after all), and won't adversely affect computer or browser performance. Just click on "Get Google Chrome Frame" to perform the upgrade. Alternatively, you can access iBoku with the Google Chrome browser.