A packet of barbecue flavoured rice crackers.

Me. A cold night. A game of Spira-Defense. A packet of barbecue flavoured rice crackers.
A high carb snack - yes, but since I'm only having a few, and it adds up to less than 20g carb, I'm not bothered.
Lets see... 21g carb per serving, 4 servings in a pack, so if I have less than a quarter of a pack I'm having less than 21g carb, right?
In which case, the 3u I take to cover it should be just a little bit too much, especially as I started at 5.3 (nice!), right?

Sooooo why is it that I end up over 10mmol a couple of hours after eating these, having already taken a 1u correction dose?

You'd think - well ok, I'd think - that eating so little carb, and overdoing the insulin (even if it is only by about half a unit) and starting at a great place, AND jabbing early to give the insulin a head start - that's about perfect, isn't it? Should end up on the low side and then - yay - I could enjoy 1 or 2 squares of yummy caramello chocolate before bed.

But alas... no choccy for me tonight. (Everybody say awww)

So, does the packet lie?
Are rice cracker carbs different to other carbs (!)
Did I get my dose wrong, run out of insulin in the pen, inject an air bubble, or maybe miss my leg and inject my chair?!?! Nope.

When something so simple goes wrong once I can understand it - there's always a reason, even if I don't know what it is - no worries, move along, fuhgeddaboutit. But when the same thing happens with the same snack two nights in a row there's something weird going on. I have learnt already that rice crackers are pretty evil to my blood sugars, but surely they can't be THAT evil? The only other explanation I can think of is that the packet is lying about how much carb is involved. But then, it admits to being 84% carb and you really can't get much higher than that without eating pure sugar. Even if it was a little bit higher, the difference would be small when it came to my dosing, especially when eating such a small amount.

So this leaves me confused... here I am trying to be a good girl and have *ahem* healthier snacks (as in gluten free, not low carb, obviously) and it just aint working. I think I'll go back to nuts & apples... and chocolate ;)

Does anyone else have trouble with rice crackers? Or is there some other food that gets you confuzzled?