GS and Firefox 9

The following is coppied and pasted from a post made by LoungeLizard on the transitional forums that were lost:

#1) I have a number of different machines on different OS's (Windows XP, Win Server 2003, Windows 7 Pro, Windows Vista, Windows Server 2008 R2) and having different versions of Firefox. So, this is not something that's specific to a version of Firefox from v3.6.25 up to v9.0.1. I am a software development professional... #2) I am running version 1.16.1 of Blank Canvas Signatures. #3 is confusing to me, what do you mean by 'from addresses'? I do in fact have a number of gmail accounts, each of which has a purpose. #4) If this is referring to the confounded GMail UI change - yes, I am; but it doesn't matter if I revert back to the old UI - the issue I am having happens on all instances regardless of platform (except on my Linux machines which do not have GS). #5) This issue has nothing to do with themes or the particular ''look 'n feel'' - it is consistent across a number of different instances each being different. #6) Yes - 3 Labs: Mark as Read Button, Signature Tweaks, Unread Message Icon. Though I noticed this behavior BEFORE I enabled those labs - it was because of this behavior that I dug into the settings of GMail and found the labs in the first place. Those 3 were the only ones that I thought were useful to me - I now have those three enabled on all my machines.
#7) Add-ons - different machines have different add-ons, I have bunches of add-ons, too many to list - so many on a couple of machines that I use vanilla Chrome if I just want a quick google search or something.

The Problem
I am noticing a consistent problem with GS since GMail has changed. Every time I open GMail, I get a dialog window pop open containing a bunch of javascript code (I have it captured, and attached) containing a statement TypeError: gmailInstance.mainElementWrapper[0] is undefined. This dialog pops up 4 times.

I really like GS - been using it for quite some time; but I am getting annoyed and irritated with this pop-up window I have to kill each time. I am seriously considering uninstalling (just saying, not to be viewed as a threat or nothing) since I'm not sure if there's other consequences I'm not aware of. I say this because I've been having some strange issues periodically, none repeatable and none specific and none consistent, but all related to one or more GMail's open in a tab. Every time I get a error dialog reporting some error and it mentions BlankCanvas as a culprit.

The only thing regular and consistent is GS. I have not taken the time to strip out Firefox and all Mozilla-domain files from one of my machines to troubleshoot this issue. I simply don't have time at the moment for something like this. Simplest solution for me is to eliminate GS and get by without it. But, *sigh* I feel reluctant to do so - I really do like this app.

-- LoungeLizard