Is it possible that the issue is rather the combination of Canon's AVCHD flavor and AIC? I've been using AIC for years without any problem in FCE/FCS, even the few times I had AVCHD on my desk.
I could imagine that AIC doesn't really know what to do with the modern, higher bitrate compression schemes that are used, compared to the original AVCHD.
Try to shoot the old fashioned 17mbps if you get the same artifacts.
AIC is a nice codec, but it's getting a bit long in the tooth, and I'm not sure if Apple has ever updated it.
I could imagine that AIC doesn't really know what to do with the modern, higher bitrate compression schemes that are used, compared to the original AVCHD.
Try to shoot the old fashioned 17mbps if you get the same artifacts.
AIC is a nice codec, but it's getting a bit long in the tooth, and I'm not sure if Apple has ever updated it.