Faders rubbing

Anyone else have a problem with the bottoms of the fader knobs rubbing/scraping the faceplate of their WHIII? What causes this, and how do I fix it?

Edit:

I called HES and spoke with Chris Litz who said the earlier faders were problematic in this way, and that a quick fix is to use RTV silicone under the faders to both anchor them down, and to give them a bit more height. Newer fader designs are taller, and do not have this problem.
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