[Walking in one place problem... Help?]

I, having problems just walking, when i walk straight i walk in place, when i stop i jump places, only when i walk side ways i move but never straight, any helps?

(Also i dunno how to reply to previously answered post, help there works too)

[How to run SL at best setting for optimal performance?]

im currently running a Windows 7 Home Premium 64 Bit ediiton with

Intel Core I7-2670QM Quad-Duo CPU 2 2.20 GHZ

 

8 GB Memory RAM

 

Intel HD Graphics 3000

 

At 1920X1080 32 Bit color detph.

 

With the Second Life Viewer graphic setting set between Low And mid and having very bad slow down issues. Can someone assit me please?

 

(also, i dunno how to reply to answers, my first time using this, so help is appreciated)