Is it possible a client residing in US the first six months and the other six months outside US. Myquestion is it possible has to file dual source income one for 1099 and one for 1042. Please let me know I need help!

If the income exceeds the filing requirement, your client must file tax return and report all the income. Normally form 1042 is used to report income paid to nonresident.
1099-misc income is reported on schedule C or C-EZ. You client may or may not be liable to pay SE tax.
What visa does your client has? When did your client enter and leave US?

We also need to know HOW your client filed in 2010.