i've tried all the dlls, the original that comes with the pack and also the debug/release versions for both x86 and x64. but no luck.
So i've tried (just for curiosity) the previous version and it worked.
So i went again on the vst.net site, to see what's the difference, and in the download page i found the (very simple) solution. I don't know how i didnt see this before, but the new version of vst.net (1.1) requires VS2012 version of the VC CRT, that means that if one dosen't have it already installed (for example with visual studio 2012) he needs to install it:
and, voilà, after installing the correct dependecies now it's working.
Thanks for your support, was more simple then what i was thinking.
I suggest to put this link in the requirements, on the contribution page, so if somebody dosen't have this can download it, also because this VS2012 version of the VC CRT is not required for the correct vvvv installation, so it's not sure that one have it installed (like it happened here in this computer). I think windows 8 has it by default, because i've never needed to install it before, but here i'm on win7, and it's the first time i'll use this pack with this version of windows on a fresh new machine.
thanks again for help, happy it works :)