warrant in CA

I have recently been fired from a new job because a background check showed that I had a warrant. My best guess is that it is from a petty theft I was cited for roughly 6 years ago. My questions are:
1) Why, during traffic stops and other background checks, have I never heard of this warrant?
2) Is there a limit as to the time in which they can serve me a warrant?
3) Is it possible to transfer the warrant to a different court?(The issuing court is in Southern CA and I am up north)

Thank you for any help that you may be able to offer.

[calatty]

Maybe one of the agencies just updated its records. Once a warrant has issued, it is good forever, i.e. you do not get rewarded for eluding arrest. The matter will not be transferred to the court of your choice for your convenience. Get a So. Cal. lawyer, and arrange to take care of this matter.