As was stated below, if you already have the IE version install, you can just get the plugin dll and put it in your Firefox "plugins" directory and restart FF, and you should be good to go. If you can't find the dll, I have uploaded it to: http://c.mfcreative.com/affiliate/ceg/npImgCtl.dll
I will try to remember to remove this when the xpi fix is published so that version problems don't happen.
Sorry for the inconvenience. I know they have a fix close to release, but I don't know how far off they are from releasing it yet.