Hey guys i had my first gig the other night so took my serato along and it worked fine, i rocked the place and came home:)

now i am trying to set it up on my home system but when i assign a track to a deck and play it the track doesnt play propely and keeps sort of shuddering along slowly. Does anyone know what i have done?

Thanks in avance

Calibrate your setup again. Every time you take it to a different venue you need to do this to adjust the threshold setting to get rid of unwanted ground floor noise. Its different everywhere you go.

would that make the tracks shudder?

yes

What if one table works fine and the other doesn't even after recalibration?

bones,

That would probably mean that the turntable has some sort of short either in the needle, tone arm, or RCAs. Clean the contact points inside the tone arm with rubbing alcohol first and try switching needles. If the problem persists you will probably need to get the turntable serviced.
In the future please post your issues in a seperate post so we can keep the topic on hand organized and on track. Thanks:)