Differences in breakpoints between browsers

So I have my suffixes setup as follows:

_mobile - default
_narrow - 739px
_normal - 979px

Force Resize = yes

I also have the Omega Theme breakpoints set change at the same time (narrow at 740px, normal at 980px).

Works well in Chrome, Safari.

In FireFox (using the web developer toolbar), the image changes from the normal style to the narrow style at 996px, before Omega has changed the layout. Then the image changes from the narrow style to the mobile style at 756px (instead of at the expected 740px).

This seems, simply, to be an issue where the value that '$(window).width()' retrieves is not consistent between browsers.

Setup everything as it should (breakpoints that match Omega Media query layout changes) and it works fine in Chrome and Safari. In FireFox and IE9, the images controlled by Responsive Image and Styles are offset (in FF, by 17px.. the size of the vertical scrollbar).

If you'd like more info about the issue and perhaps some possible solutions that can be built into the module, see:
http://stackoverflow.com/questions/8472566/how-do-i-get-css-mediaqueries-to-work-with-jquery-window-innerwidth
http://www.quirksmode.org/blog/archives/2010/08/combining_media.html (in the Javascript pairing section)
http://stackoverflow.com/questions/833699/clientheight-clientwidth-returning-different-values-on-different-browsers

Is there something we can do to fix this in the jQuery logic? We need to be able to call these different images in a precise manner.

Thanks!