How do you mirror weight maps?

aaráribel caađo

I can't figure out how to mirror weight maps across the X-axis. I expcted Weight Map Symmetry would do this, but if it does, it's not working for me (my geometry and bones are mirrored). I tried Copy Weight Maps, but there isn't a corresponding Paste Weight Maps, so I don't know how to use that. What am I missing? Right now I have rigging that works, but would be better with some optimization and this is making me batty!

3D-GHDesign

Weight map symmetry doesn't work well since years .... just today I tried to use it on my figure ... with mirrored arms. I named correct way ... lArm (Left Arm), rArm (Right Arm) - symmetry shoudld work, but nor the weight map symmetry menu, nor the symmetry painting didn't work :(

Mada

For weight map symmetry to work your obj needs to be symmetrical since its a polygon based weightmap - usually that's the main reason if its not mirroring, its not symmetrical. I do have to try a couple of times sometimes before it works like I want it to.