I cant remember the last time I heard this problem, and not that it has not, but its been a long while.

Anyhow does the problem change at all when the engine is running? Is there anything else that was noticed that made it shift or even sound different?

And the last thing that I can think of that could help diagnose it is what was happening when it first did this?

As much as a bent shift fork could be the cause there is also a chance that its the shifter shaft, and only real issue is that both a sort of a pain to fix.