Hive seems to struggle with files headers when loading flat files. Here's a bit of python to trim the first line (i.e. the column header line) from every file.

trimFirstLine.py

import os

dir = 'put your director in here'

for filename in os.listdir(dir):
    with open(dir+filename, 'r') as fin:
        data = fin.read().splitlines(True)
    with open(dir+filename, 'w') as fout:
        fout.writelines(data[1:])