llSitTarget()???

I have a prim on which I'm trying to set a sit target. The prim has rotation of (degrees)<0,90,315> I'm trying to make the sit target so that the av is sitting at <0,0,0> with respect to the world. But NOTHING I try seems to come close to getting it right. Changing any one parameter in increments produces WILDLY different results, and usually the av is sitting at some odd 45-degree angle.

Using: llSitTarget(<0,0,0>,llEuler2Rot(<0,PI/2,PI*7/4>);

Seems to work some of the time, but it all seems to depend on where the av is standing when you tell it to sit. Sometimes, it sits properly. Sometimes, it sits at a 90-degree angle to where I want it, and on rare occasions it actually says there is no sit targe available. I can click in the exact same place three times in a row, sit, and stand up, and it will sit in a different place/orientation each time. I haven't seen anything in LSL I hate more than the way sit targets are defined. Why not just add a flag to allow setting the target relative to world coordinates???

(I would have posted in the script forum above, but it doesn't appear to be open for new topics).