How to fix the IETab extension work under Firefox 3.6?

How to fix the IETab extension work under Firefox 3.6?

I'm a happy user of Firefox, but I sometimes need to access sites using IE (at work, mainly). Until now, I've used IETab which works fine... until you want to update to Firefox 3.6. The update program says it'll disable the add-on, and that's something I'd rather not do.