I saw it as a big problem, big enough that I spent about 2 hours trying to solve it, and was willing to keep at it until it was solved even if it to me 100 hours. I need my administrator to be able to edit the site even if he or she uses linux (which means he or she cannot use IE...).
Thankfully, the solution was rather simple once I stopped trying to tweak the code and started researching about this third party control Free Text Box... I upgraded from version 3.1.5 to 3.1.6 (overwriting all files installed by DashCommerce) and voila! Firefox works. Incidentally, it actually works better in Firefox than in IE now on some minor issues, which is good, since in this case, the administrator will only be using Firefox to administer the site.
I have to say that I am sick of the "well, all the other CMS require you to use IE, why should this be any different?" This software is Open Source... in light of that, the community expects more. They expect to be able to use Open Source browsers with this open source software. They are told it is cross browser supported, yet this is the response? YES. It is important that the admin page function in 2nd most used browser available which works on every major and most minor OS platforms. IE does not run on linux or Unix, delays releases for Mac (if they will even release another IE for mac... who knows?), so Firefox is the most important browser simply because of it's support to run on practically anything that calls itself a computer (I even got FF2 to run in Windows 95 for a customer... talk about compatible with any OS).
Anyways, since I'm "new here" and don't know how to do anything with the bug system, I thought I would put the fix here for those that will search later.