Tuthrick: IWD1 has the re-roll option, since it's based on the AD&D 2nd edition system. Whereas IWD2 is point-buy, and it's based on D&D 3rd edition. You're probably playing IWD2 and there's no option to re-roll, by design it's a point-buy stats distribution.
I can assure you I am playing Icewind Dale Enhanced Edition, not IWD2. IWD2 isn't available on steam. I can see the reroll button, but its all grayed out. All my stats start at 10 and I have 20 points to put in, with increasing usage as we get higher in modifiers just like a point buy system. I've never seen this in IWD1, and am quite familiar with it and IWD2. I'll try and upload an image when I get home from work because this is boggling my brain at the moment.
Tuthrick: IWD1 has the re-roll option, since it's based on the AD&D 2nd edition system. Whereas IWD2 is point-buy, and it's based on D&D 3rd edition. You're probably playing IWD2 and there's no option to re-roll, by design it's a point-buy stats distribution.