Really? IW at SSE4.1? You have my same CPU, my graphich card is better, my ram is 8GB, WHY!!!! But I've got a lot of problems because it go slow when I do KameHameHa or when I transform... For example in game (when I kick, or other moves ex. Rekoom Kick) I've got 60-65fps only in SSE2, but when i do KameHameHa or Final Flash, Masenko etc.. I've got only 35fps... It's an horrible gaming !!! D:
Edit: I've downloaded the SVN r5139 and I've had 2 .exe: pcsx2.exe and pcsx2-r5139.exe. Which must run?
PS: It's x86.. Is there a 64 bit version? ... It doesn't use all my PC performance...

Run any of it;P, it's named like that to help testers who unpack more versions to one folder(then each version has own number and the latest is without one).
I have much worser system and aside from mtvu hack I don't need anything for this game to run easily at full speed, it's not soo demanding graphically either on my hd5670 no problems with full hd res and in most games I need a bit lower internal res. If the game's working for you faster on SSE2 no need to force yourself to use SSE4.1, the gain whenever it could happen from it would be minimal, and while it's seems opposite for you in negative way, just don't bother with it.;P

Edit: and oh, there no x64 pcsx2 version, 32 bit works as good as it can even on 64 bit systems.

To back that up, I have a 64-bit system and it works great for me.

How to enable MTVU? I don't found it o.O

It's a speedhack(Emulation Settings>Speedhacks) in svn versions.

you can find the svn versions here: http://www.pcsx2.net/svn.php