It would be nice to know if it's just the 135's or if it's a general Zuiko problem. (I don't mean to hijack the thread)

No problem! It's good to see that people read these things I think it must be a general problem, as all the Zuiko lenses I've seen look the same a the back. The tiny plastic pegs which hold the spring in place do look very fragile. In my case, the lock button had been held down for several days by very tight inflated ballon-type packing, which is why I think it failed. I'm much happier now that it's superglued as well, as it's not very good fo rhte lens to have the spring rattling around inside (shudder!).......