[arch-general] Super weird dd problem.

Hello, So I was creating a archlinux usb bootable drive: [root@masterkorp-laptop Downloads]# dd bs=4M if=archlinux-2013.06.01-dual.iso of=/dev/sdb 130+1 records in 130+1 records out 548405248 bytes (548 MB) copied, 0.964976 s, 568 MB/s I was like WOW, this was too fast! But nothing ever gets written to the pen drive. To add to the weird factor, a dd to dev/sdb1 (partition) works as it should, slowly. But then ofcourse the iso gets unbootable. The md5sum on the iso is correct. I tried with diferent pen drives. Please, any suggestions is welcome. -- Regards, Alfredo Palhares