Not true, in X2 when rendering AVCHD to MPEG-2 (what obviously disables SmartRender) the blips were present.
Indeed there is, my mistake, I just discovered this problem after doing some more trying out with various versions yesterday.
I've seen two problems I think with X2:
1) Blips around transitions going from AVCHD to any format, so not related to SmartRendering, as there is no SmartRendering when converting to a different format.
2) When SmartRendering to an AVCHD file, the file has the blips, but is also not perfectly created, as the SmartRendered AVCHD file can have all sorts of strange issues when converted again to something else (may just be related to the particular format from the Panasonic SD9). For example sometimes after a transition the resulting video is covered with blocks like major drop outs.
With X3 1) is fixed, although in case 2) I still sometimes find the resulting AVCHD file becomes corrupt after a transition, not all the time, but quite often. This means SmartRendering out as AVCHD to get a master to then use to produce the formats required I can not do.
Additionally with X3, SmartRendering or no SmartRendering and creating out an AVCHD file, there is a noticeable reduction in picture quality during the transition, try a 3D transition with a complicated scene and the results are far worse than I would expect.
Just my findings.