Thanks Kevin for trying to help but your answer is pretty pretty basic. What's next? the definition of an O.S.?
Maybe i'm the one who can't explain the issue...
Anyways i found an answer for my question, the BEST scenario is having the main HDD as disk 0 and the SSD for caching as disk1 not the other way.
I had them the other way for almost 2 years (nobody tolds you how to correctly setup) so each time i installed windows 7 on disk 1 sometimes it created me the 100mb partition on disk 0 and i've never wanted that and i didn't know that windows 7 installs that partition on the first disk available (for me disk 0 SSD) and that was driving me nuts.
That's the reason why the 100mb partition was taking part of the cache array sometimes (first pic), and that affects ofther things.
Now i changed the disks order and found my self an answer to my question.