Hmmm... Interesting... I have that issue on a couple of my USB flash drives, and on one of them in particular, no matter what I do, it eventually happens again. If I re-format it then it lasts a few "plug-ins", but eventually the issue will start again... It seems to only affect USB drives with the U3 software on them on my PC, but it is very annoying... Hopefully someone can find a somewhat easy fix.
Poked around inside svchost.exe that looks like no-go. After seeing secr9tos sources, maybe the pop up is called from inside a PNP driver, I have about 10 USB*sys drivers so I'll start there.
This only happened to me when I remove my USB drive without using the safe remove feature. I have about 6 USB devices attached with no issues. This happens everytime you plug some device?