I have a similar erro, with a Raspberry Pi with Minera 0.4.1 and a Antimer U3 with the original PSU.

The error say:

[2015-03-15 22:15:50] Accepted 0ea14cda Diff 4.48K/256 AU3 0 pool 2
 [2015-03-15 22:16:27] Accepted 90b4ee50 Diff 453/256 AU3 0 pool 2
 [2015-03-15 22:16:42] AU3 0: No valid hashes for over 1 secs, attempting to reset
 [2015-03-15 22:16:42] AU3 0 attempted reset got err:(0) LIBUSB_SUCCESS
 [2015-03-15 22:16:49] AU3 0: No valid hashes for over 1 secs, attempting to reset
 [2015-03-15 22:16:49] AU3 0 attempted reset got err:(0) LIBUSB_SUCCESS
 [2015-03-15 22:16:58] AU3 0: No valid hashes for over 1 secs, attempting to reset
 [2015-03-15 22:16:58] AU3 0 attempted reset got err:(0) LIBUSB_SUCCESS
 [2015-03-15 22:16:59] AU3 0 SendWork usb write err:(-9) LIBUSB_ERROR_PIPE
 [2015-03-15 22:16:59] AU3 0 attempted reset got err:(-5) LIBUSB_ERROR_NOT_FOUND
 [2015-03-15 22:16:59] AU3 0: Comms error (werr=-5 amt=32)
 [2015-03-15 22:16:59] AU3 0 failure, disabling!
 [2015-03-15 22:17:13] Hotplug: Icarus added AU3 1
 [2015-03-15 22:17:24] Accepted 56d7767f Diff 755/256 AU3 1 pool 2
 [2015-03-15 22:17:47] Accepted 97bdd8d7 Diff 432/256

  My provisonal solution is unplug and plug the USB conector of Antminer.

I need help !!