Yep, it's very common. Significant stress can & does easily send my blood sugar into double figures when I know without the stress (i.e. If I'd had the same meal and the same bolus and was having a lovely calm day) it would be fine.
I think (i.e it's just my poorly understood guess) it works like this - stress, proper stress, will give a fight or flight reaction. It makes your body release adrenaline - the adrenaline blocks your insulin sensitivity, so while that's floating round your system your are going to climb. Try to be cautious about correcting for stress, because when you relax you are likely to drop like a stone.