NO joint sponsor needed if your current income exceeds 125%, the I-864 indicates only past year's return is required, that shows you over. 2005 and 2006 returns are optional, you can also attach an employer letter indicating current salary, and a copies of a few recent pay stubs.
Note: if income is at or above 125% then you can use the simpler I-864EZ form. (I-864EZ is for cases where Only One immigrant is being sponsored, NO Assets being used, and NO Joint sponsor)
SEE Your other post:
http://www.visajourney.com/forums/index.ph...=116712&hl=
http://www.visajourney.com/timeline/profile.php?id=43289