Finally some other people noticed.
It has been behaving strangely since this morning!

I bragged that I have lots of experience in mining, but what I see is a first for me,.. no EXPLANATION at all.
But I would bet its not a 51%, nor it is a FORK.
For 51% someone needs to take over ultracoinpool,....

I'm switching to ultracoinS please join me:
http://www.ultracoins.info

I will push everything I have but I can hardly reach 1,500MH/s or 20% of the total network, need someone to join me!!!