Infra8 on firefox

Infra 8 only supports MSIE 5.5 or above ( and now MSIE 8 in RP 37). The Infra controls use ActiveX which is not included in Firefox and is why it is not working for you. There is an ActiveX plugin for Firefox, but I have never tried it so I am not sure if Infra will run correctly using it.

I use IE Tab (https://addons.mozilla.org/en-US/firefox/addon/1419).  It enables you to use the embedded IE engine within Firefox.  All you have to do is tell it what urls should use IE.  Whenever you enter that url into Firefox, it runs IE within the Firefox tab.  The tab has a little IE logo on it to let you know.  You aren't really running Firefox but you don't have manage multiple browser windows either.  I haven't had any problems using Infra8 this way.