Strange transparency bug?

So I'm attempting to do a ruffle on a gown at the neckline, but have it simulate a transparent fabric like tulle. Anyways, my avatar is using a prim hair that involves lots of curls down the back. For the most part, everything looks fine with the ruffles and the hair...until I set the transparency up to about 40 on the ruffle texture. At that point, the ruffle usually shows on top of the hair...the transparency actually makes it more visible!

Is this just a bug in SL or is there some way to work around it? I suppose I could mess around with the texture itself, but prefered to do it the easy way first.

You have encountered the famous Alpha Sorting problem.

Actually, you're lucky you're not seeing it right away; it can show up on a prim that has no transparency, if the texture on that prim was saved as a 32 bit Targa. (Which is why it's important to save as 24 bits, if you don't want transparency.) It can show up as soon as you reduce the opacity of a prim at all.

You'll also see it around your hair when you stand in front of a window, or when looking at the trees and flowers that people build. In fact, most of the fire in-world wouldn't work, if it wasn't for this particular bug.

There isn't a real work-around; all you can do is avoid the problem by making sure that two prims with transparency don't overlap. Usually, this means using opaque prims behind the transparent ones.

"Messing with the texture" doesn't help, because it happens when any two objects with any transparency in their textures overlap. Most of the time. Sometimes, they are fine, and it seems to have something to do with line-of-sight. But I haven't been able to pin it down reliably. (Many have tried, but so far, no-one has found anything that works every time, to the best of my knowledge.)

Sorry that I can't give you a better answer.

Edited to add the last paragraph.

Well, at the very least I won't be searching for a solution that doesn't exist yet.