What is the concerntration of player and objects in kavala on both servers? There may have been only 20 people on s1 and 30 vehicles in kavala, however on s2 there may have been 35 people and 45 vehicles in kavala.. They could have been doing stuff that uses a lot of the animations/scripts therefore stressing the server more...
Are you playing on the same profile?
Is this a recurring issue? (Ie does it happen everytime you play on s2? Or is it a one off?)