Kubuntu with KDE 4.2 runs too slow

Hey Guys!
I was using Ubuntu 8.10 for a longtime now, and i just installed Kubuntu with KDE4.2. The looks are awesome and definitely leaves Windows Vista far behind. lols... Ok but the problem is my machine Lags a lot and sometimes stucks for a minute or so only mouse moves! Now that is not a good sign...!
Help guys!

Does your system configuration meet the minimum system requirements of KDE 4.2 Or try downloadin KDE4.2 package for your CPU from here :
Download KDE 4.2

Hey!
Yeah...! My config is : C2D@2.66Ghz, 2GB DDR2 RAM, 512MB GeForce 8400GS, 160 GB HDD, Sony DVD-RW. Any other suggestion??

Hey..!
Thanks for the link... The version which i have is the beta version and the link you provided is for the stable verion... Thanks man... Can't wait to get my hands on it...!