I have installed Mobile Joomla on a site and it works great on most phones. But on the Samsung Blackjack II (i617) I keep getting and Active X warning sign to install, is there a way to remove this?

What is the url of your site?

www.imperialhealthcarecentre.com/

This is the site.

Hmm. WURFL supports this device.
Do you use latest version of MJ? Did you have any errors/warnings during install?

I installed an older version which gave me errors, so I removed that one and installed the newest version, with no errors.

Could there be something that triggers the active X controls in certain phones?

I've tried to emulate your Samsung useragent string, and it seems that your site return desktop page for this devices. The possible reason is that TeraWURFL plugin is unpublished or wasn't installed correctly. Try to reinstall MJ and check that this plugin is published.

Anyway, your site doesn't contain any ActiveX object, so it may be issue that relates to phone itself, and not MobileJoomla.