Question on Stat draining abilities

[Apokriphos]

Several NPC's cast stat draining spells of different types all over Neversummer 4, and this is especially prominent in the Shadow plane.
However, I have noticed that although my character usually beats the saves on these spells, every single time he still receives the corresponding stat penalty.

I am not sure if this is an intentional modification on behalf of the dev's or default nwn rearing its ugly head, just looking for some clarification - flame war not included

[LinuxPup]

Lots of creatures in HoD, Neg. Plane, and shadow plane do ability damage with no save. The save you made is probably on the normal damage, not ability damage.

Sort of like neg. energy burst...

[Apokriphos]

The stat drains I am referring to definitely come from spells which make save checks, and yes, Negative energy burst is one of them.

I didn't want to reveal them all by name since what I am doing already seems somewhat taboo

[Sparky]

Some spell's and ability's effects aren't completely negated on a succesful save, mearly diminished.