Hi Subaru,
In case you did not see my response to your post in the PHD2 forum, I'll repeat it here...
If there is an issue with 2.6.2 we'll need your help finding it since we are not hearing other reports and I am not aware of any code changes between 2.6.1 and 2.6.2 that would affect dithering or SGP communication. It would be great if we could see your log files from a session where you encountered the issue with the latest phd2 (v2.6.2 or the latest dev build 2.6.2dev3). PHD2 debug log and guide log and SGP log would be most helpful.
Thanks,
Andy