When I'm wearing the shrouded boots (from the Dark Brotherhood) in Solstheim, there are no footstep sound effects when walking on the ash-textured ground. I know that it says I'm supposed to move silently when wearing them, but I've had the shrouded boots since the first week that Skyrim was released... and this has never happened before. It's not any huge technical problem or anything, but it's pretty annoying and I can't help but feel like it's a glitch that could be very easily fixed.
My guess is that for each texture there is are sound files for each boot/shoe type, and in the instance of the shrouded boots on the ash texture, the sound file is missing. Just put the same sound file in place for the ash texture as what's used for the snow texture. That would surely be close enough... and it would only take a few clicks.