I'm having an issue with the first variation drop down closing almost immediately after clicking into it in all versions of IE. You can check it out in action here: http://www.acala-farms.com/product/gift-box/3-bottle-gift-box/
I've tried everything, reverting themes, deactivating plugins, etc. and I finally narrowed it down to regular old @font-face rules in my CSS. When I remove the @font-face rules, the issue is fixed.
Does anyone have any ideas? This is driving me nuts!!!