Hickory: BG and IWD (don't know about PST)
No. Ability scores affect many things, and the manual will tell you that WIS affects magical defense saving throws, but this is in error (not implemented) -- saving throws are table based, and are determined by race and class. The only ability scores that directly affect saving throws are what is referred to as 'shorty' saving throws. These are CON based bonuses granted to Dwarves, Gnomes and Halflings.
Hm .. I don't ever remember hearing about the so-called "shorty" saving throws. It has been a while since I read the manual. I have no idea how this concept works.
Good to know. I don't know if ability modifiers for saving throws exist in the core rules but it would be nice if scores did affect saving throws. At least now I know not to worry about low scores in abilities not suited to my class.
Thanks again, Hickory.
edit: BG2 manual states that thief skills receive racial and dexterity adjustments.