1.6.3:
ubuntu@domU-12-31-39-06-B2-05:~$ /opt/mongodb/bin/mongoimport --drop -d testdb -c testcol < test.out
connected to: 127.0.0.1
dropping: testdb.testcol
16400 5466/second
34900 5816/second
52300 5811/second
71300 5941/second
90100 6006/second
imported 100000 objects

1.7.5:
ubuntu@domU-12-31-39-00-88-F5:~$ /opt/mongodb/bin/mongoimport --drop -d testdb -c testcol < test.out 2> /dev/null
connected to: 127.0.0.1
dropping: testdb.testcol
1172890/18446744073709551615 0%
14800 4933/second
2852890/18446744073709551615 0%
35800 5966/second
4388890/18446744073709551615 0%
55000 6111/second
5996890/18446744073709551615 0%
75100 6258/second
7756890/18446744073709551615 0%
97100 6473/second
imported 100000 objects

Maybe some extra debug? The import seems to work fine.