I’ve been working on a dress (for Second Life) for the last couple days and finally moved onto weight painting. I seem to have a problem though, as no matter how heavily I paint on the dress under the arms, it just won’t move correctly with the body. I can’t edit the mesh of the dress directly as that would ruin the shape in any other pose.
In an attempt to try and find a solution myself, I ended up going against most tutorials I’ve seen and unchecked vertex groups on the armature modifier and checking bone envelopes instead, It fixed the underarm issue immediately, but it seems any weight painting I do without vertex groups checked, has no effect. Having both checked just brings back the initial problem.
I can hide most of the body with an alpha clothing layer in SL, but this particular problem spot wouldn’t work too well if I did that. I’ve also seen other similar items by other creators that didn’t have my particular issue in their finished product, so there must be a way to fix it. Which is what I’m asking now.
Here’s a couple screenshots of the problem:

