My understanding is that the selector bent which means that it wasn't fully engaging the gears. This has caused damage to 5th gear making it difficult to engage, although once in it doesn't pop out. I also had issues shifting down into 2nd on occasion. When it first started happening I thought it was me not being positive enough with the shifts, turns out it wasn't :-( From what I've been told it may be down to using a quick-shifter.
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