I have a Kershaw "Ken Onion" spring assisted folder that I have carried for probably more than 10 years. The spring stopped working about three years ago, but other than that no problems ever. It has seen a lot of use, and holds an edge very well. It is the model with the regular blade. I have no use for that serrated business. I'd send it back to have the spring replaced if I could ever remember to for long enough. I think ODA sold them for $65, maybe? Great knife.
Is it a Blur or something like a Leek? Ken Onion make quite a few different models for Kershaw over the years.
KAI will fix that up for you quickly (I think if you call and ask, they will send you a tortion bar so you aren't without a knife while it's gone).