Yes - that might make a difference...
First of all - you need to determine if that were two assignments or one assignment...
As you are working in NC - your income is considered from NC sources and therefore is taxable for NC regardless on your residency.
If in Mar 2008 your residency changed from CA to NC - you should file as part year resident for both states - with your income from NC to be taxable only for NC.
If your residence was not changes - you should file NC tax return as a non-resident, and CA tax return as a resident - so all income will be taxable for CA and on CA tax return you will claim a credit for taxes paid to NC.
According to the IRS - please refer to the IRS publication 463 - http://www.irs.gov/pub/irs-pdf/p463.pdf
Generally, your tax home is your regular place of business or post of duty, regardless of where you maintain your family home. It includes the entire city or general area in which your business or work is located.
Once you have determined that you are traveling away from your tax home, you can determine what travel expenses are deductible.
You can deduct ordinary and necessary expenses you have when you travel away from home on business. The type of expense you can deduct depends on the facts and your circumstances.
If you have several consecutive assignments in the same area/location for more than a year - your assignment will not be considered as temporary and you tax home will be changed.
However the IRS doesn't define the save harbor period between two assignment.