In my experience, the front usb ports of desktop pcs are often prone to flaky behavior
##Front USB 3.0 user@crash:~/maemo$ sudo flasher-3.5 -i flasher v2.5.2 (Oct 21 2009) USB device found found at bus 006, device address 047. Found device RX-51, hardware revision 2204 NOLO version 1.4.14 Version of 'sw-release': RX-51_2009SE_21.2011.38-1_PR_MR0 ##Rear USB 2.0 user@crash:~/maemo$ sudo flasher-3.5 -i flasher v2.5.2 (Oct 21 2009) USB device found found at bus 002, device address 017. Found device RX-51, hardware revision 2204 NOLO version 1.4.14 Version of 'sw-release': RX-51_2009SE_21.2011.38-1_PR_MR0