Checking out the source code, this isn't going to work in IE8 and earlier without some small tweaks. IE didn't support `document.getElementsByClassName(string)` until IE9. It would be a small rewrite to make it work with IDs instead of classes (or you could use a shim).
[EDIT]: . . . But I like the idea. Might even use it next time I'm working with GA.
Thanks for the warning! I initially developed this with jQuery, and only after seeing how little of it was needed decided to get rid of it - but I forgot to make all the due diligence. Later or this weekend I'll fix this - but if in the meantime anybody wants to send a fix or a pull request, I'll be glad to use it.
LOL, I had forgotten: I already use a custom getElementsByClassName if there isn't one! So the it already works in IE < 9... check out the source code :)
[EDIT]: . . . But I like the idea. Might even use it next time I'm working with GA.