I suppose pretty much all of these issues should be fixed - until the next generation of cams messes them up again. Can't say more, since, except for a few test clips, I don't work with AVC stuff.
I was demonstrating After Effects and Premiere Pro at the NAB trade show last week, and this was a common question. I asked the people who had had bad AVCHD experiences to bring me their bad media, and we could try it out right there on the show floor. Three people took me up on this and brought me USB drives with clips that had failed to import correctly using the CS4 applications; and they turned out to work fine using the CS5 applications on my computer.
Sounds great, thank you for the reply.