They sure have Andrej.

See this discussion: http://line6.com/support/message/352922#352922

My four are holding up well (in use since last November), but maybe they're from an earlier batch.

I did, however, take particular not of the "do not over tighten" warnings in the instructions and always brief performers accordingly: ..."If you squeeze, drop or try to unscrew anything, you'll face the wrath of Ron !" ...or words to that effect.

In Line 6 terminology, the replacement's identified as pn 30-27-0434, but, as yet, I've been unable to get an estimate of its cost. Knowing Line 6, I'm sure it'll be reasonable.