This is just a quick update to let everyone know I've finally figured out why the dynarec wasn't working in Super Smash Bros. The problem has taken a lot longer to identify than I'd hoped - in part because it was a particularly tricky bug but also because I've not had as much time to work on Daedalus recently as I would have liked.
Anyway, I managed to spend a few hours this weekend isolating the problem, and after a little experimentation I've been able to come up with a temporary workaround. With the fix in place SSB is running at around 30-40fps in game on the PSP, which is very exciting.
Now that I've identified the problem my next job is to come up with a permanent, robust solution to help fix similar problems in other roms. I also want to add some improved checks in the debug build to help spot other situations where this problem arises.
For those that are interested I'll post an update shortly (within the next day or so) with some of the technical details.