Mileage reimbursement lumped in on 1099-MISC.?

My employer contracted me out to another business to do computer training and gave me a 1099-MISC. I billed my employer $2000 which is included in box 7 (non-employee comp)on the 1099. That part seems ok. However, I also go to company sponsored meetings and am reimbursed for my mileage. My employer lumped in the mileage ($400) on the same 1099. So, box 7 reads: $2400. Since the mileage is a reimbursement, should I deduct $400 worth of mileage on the Schedule C? I don't see why I should pay tax on a reimbursement and for something I could normally deduct. Any thoughts on how to go about this? Thanks!