You've got a lot of variations on that particular product, don't you? I had a similar issue, and had to move to a less helpful variation matrix. Couple possible issues that I found that might help you:
if you're on dreamhost (or maybe other hosts): http://wordpress.stackexchange.com/questions/53750/woocommerce-too-many-variations
what seemed to be causing the error for me, and I fixed by just reducing the variations (for whatever reason, i've found php 5.4.x to work best for me on dreamhost...not sure if this is what's causing the errors for me, and if I stepped back to 5.3.x it would work better). I definitely don't know what this is all about, and I didn't even try to muck around in my htaccess, because I'm not even sure suhosin is running on my server...:
http://docs.woothemes.com/document/problems-with-large-amounts-of-data-not-saving-variations-rates-etc/
regardless, moving to fewer variations fixed it for me; I just had to have some that were "any ____", instead of defining each one as a separate variation. Obviously that doesn't work for everyone, but it's a stopgap fix for me at this point so things actually show up on the site like they should.