I came across the problem a while ago but saw a few comments about the problem. Ishi had helped me fix the problem when I originally had it.

So it seems like your model is jolting forward when walking or it feels like its lagging, sometimes its only you that has this problem.

First of all its not a hard fix at all.

1: Remove any leg addons that allow you to view your own legs, such as GLegs etc. (they are pointless anyway - no offence)

2: There is a thirdperson addon that also conflics and somehow causes a problem. The best working thirdperson addon would be the one with sliders, use that.

3: PAC, depends what someone is doing with the PAC but its caused me problems before and also a couple of friends. [Test your pacs, whitelist and blacklist pacs]

I hope those three somewhat fix your problems, have fun everyone.