I edited the message. please re-read
Thank you for the answers, I am concerning about two issues actually,
First, PoW diff is adjusting while mining PoS blocks,
From the source codes which has been posted before,
It can not be happen,
Maybe the code has been updated, so, I do not have a major issues here
Because of it is same as before,
Second, Diff looping,
When small number of PoS blocks between PoW (0 ~ 5.....), Diff is increasing fast,
and, it is going to 3~5.xxx
after mining huge PoS blocks such 10, 20,.... some time, more than 40.....
it is come back to 1~2.xxx
Actually, it is the old problem, not a new issues,
my guess,
when mining small number of PoS, it is not have time to adjust Diff to matched on 30 seconds,
so, it has relatively lower Diff and block time.
unfotunately, when calcuate Diff of PoW, this block time has applied to changed PoW,
so, Diff of PoW is keep increasing
if Diff of PoW is going up to some limit or Unluck situation,
there are many of PoS is generating again, PoS can have enough time to adjust its Diff to match on the block time.
when PoW has found, PoS has stabled, and PoW will have good time gap because of the effect from PoS has minimized,
so, Diff of PoW is returning to the normal level,
This situation is repeating again and again,
History
Diff looping issues are started long time ago,
When PoS has disabled, this problem is not happen, becasue of there is no PoS to affect on PoW block time (Diff calcualtion)
At begining after resolved PoS issues (QT 1.3), this problem, because of there are large number of PoS has generated, and
It help to stabilize the PoW also,
Recently, within some time zone, there is not many coin has been mined, and so, lower number of PoS will be generated,
and, this problem problem is happen again
When generate large number of PoS is generating, this problem is gone,
IF QT 1.4 has activated ? chance of PoS will be redueced from 12X to 3X,
it menas 4X more chance to make this problem,
I worry about that,
My personal opinion about this issues,
Whatever blocktime is, Diff of PoW should be stable ~
and, PoS should be stable also,
Actually, this kind of issues are happen in PoW/PoS coins (and PoW also, if adjust diff each block)
(1) in PoW, they are failed to estimated/calcuate Diff for next block (mostly, missing or weak interpolation)
(2) in PoW/PoS, they are in the recursive calculation
Whiling writing (22:09), the diff has increased to 9 ~
5, 6, 6, 7, 7, 9, 9, n, n .....
(while start PoS, Diff has increaed so much)
(actually, it is why I have asked the reason why adjust Diff of PoW when PoS has started)
(if much more miners are mining, and PoS timing is good distributed, this problem will be gone)
(but, it become a big barrier to growing)
First, the sources on github are current. Next, the support from the people to the coin is not big enough yet to make these parameters as stable as Novacoin has, for example. Yes, it might be the diff will not stabilize more or less in the near future. We need to spread the word, push the businesses to accept grain, etc. All of us. And I see that the community does this, so I have a faith that the grain succeeds eventually.
I wanna buy 
