I too just started having issues with Iron 27.
Whenever I login to my gmail, it load up the page, but then as it loads up the side bar, suddenly "aw snap". Strangely when I log into the corporate gmail system, ie domain, it loads up fine.
I have tried disabling all extensions, and plugins, and the result is still the same. Just before the gmail loads up, if I hit the basic HTML button, then it will oad my gmail page fine, but then, it is ultra basic lacks the features of the proper gmail.
I tried deleting my default direction and starting a fresh profile, and the same result. I also tried downgrading back to Iron 25, but that too now seems to be having the same issue.
My Operating system is Ubuntu 12.04.
Is there anyone that has had the same problem and unable to load up gmail without aw snap using Iron 27 and Ubuntu 12.04?