excel, annoyance
I'm getting really really sick of the fact that excel is "smart" and redefines formulas whenever you move cells around.
It's great for when you're copy-pasting a whole table or something! But it's really frustrating when you're trying to do something with an ordering.
Even more frustrating: when the formula is part of the conditional formatting rules, and so you can't even directly see that you've moved something and now it's gone wrong.
excel, annoyance
it'd be ok if there was a way to move data around and say "hey, please don't update any formulas when I do this."
But you can't do that.
If you've got a spreadsheet that's got a lot of moving around going on, the only solution is to replace all of your formulas with ones that manually calculate cell offsets, so that you don't actually have any cell references.