I’ve noticed this as well with Sony NXCAM footage.
I drop it in a new sequence and when premiere asks to change it to match
it makes it AVC-INTRA instead of AVCHD.
I’m also seeing the yellow bar now every time.
I could have sworn when I was on CS 6.0 (now on 6.01)
if the sequence matched the footage, there was no yellow line
(even though it plays just fine with yellow line)