Pioneer DDJ S1 Help !!

Hello greetings from Spain

I just bought a DD S1 with Serato ITC 2.0 software the problem is that sometimes the controller and serato crashing .. jog leds that is playing well hung and not let me do anything, the only way it will work is entering and paragraph setup latency lower it or raise it and make changes, there is sound but the court controller becomes responsive. my pc is a i7 4gb ram and win7 ultimate 64 bits. seeing this problem I decided to try turning off Windows Aero and disabling wifi. get well take longer to fail, but eventually feel the same, I have to say also I have a Traktor controller installed on the same computer, it may be compatibility issues asio drivers??. I think it's a performance issue, and I hope so, would be solved with more RAM. thanks