I'm also using PDF X-Change
I think , you forgot to untick AskToolbar option when you'r updating PDF X-Change Viewer. Two last version forced user to install that JUNK toolbar
I have a personal site-based on Joomla and very concerned about security.
I googled and found http://www.qualys.com/forms/trials/stopmalware/ as free services.
this services can be trusted ?
I need your opinions
FF doesn't support activex,right ? thats my guess or you can try IE Tab add-onto view it.
or you can go to http://kb.mozillazine.org/Images_or_animations_do_not_load
hope helps
as I mentioned above,
if disable it > not listed in HijackThis NT services
if manual / automatic > listed but tried to fix then rescan with HJT, it still there not removed/deleted.