Just wondering if the original poster ever found a solution to this problem. I’m having the same issue. I’ve searched everywhere and can’t figure out why FCP does this. I have plenty of handle on both sides of my media but whenever I do and extend edit, the transition length doesn’t hold and turns into a one frame dissolve. I’ve also noticed that it’s not possible to click and drag dissolves to other tracks [as a very fast way of duplicating/copying transitions to other tracks] via option + click + drag. The result is the same: a one frame dissolve.
Both of these issues are resolved by trashing prefs but they only stick for so long before I start seeing them again. Does anybody know what gives here? Why does it seem that only a few FCP users experience this problem?