Also is anyone using a Raspberry Pi to do this as I want to move it to a Raspberry Pi which makes more sense power wise?
Yes and NO.
I am running cgminer 4.8.0 on Rasbian Wheezy on Rasberry Pi+. I bought two Antminer U3 but I'm just trying to get one going.
I'm getting the same LIBUSB_ERROR_PIPE you were seeing on Windows. It does recover, however, and I'm hashing at 30-50GH/s at ghash.io. When I get lots of errors, my hash rate goes down, obviously. As of this writing, I would recommend running this on the Pi since the power is almost nothing to run the Pi and a powered USB hub. The only power is really for the U3.
Good luck.
Here's my output:
cgminer version 4.8.0 - Started: [2014-11-30 20:08:09]
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(5s):23.48G (1m):36.82G (5m):40.52G (15m):33.24G (avg):41.32Gh/s
A:13232 R:80 HW:179 WU:570.4/m
Connected to us1.ghash.io diff 16 with stratum as user Universe.xxxxxxxx
Block: 7fbdf029... Diff:40.3G Started: [20:31:56] Best share: 12.1K
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SB management [P]ool management
33: AU3 33 : 225MHz 750mV | 20.69G / 36.33Gh/s WU: 576.1/m
--------------------------------------------------------------------------------
[2014-11-30 20:32:37] Hotplug: Icarus added AU3 33
[2014-11-30 20:32:37] Accepted 0868c684 Diff 30/16 AU3 33
[2014-11-30 20:32:37] AU3 33 GetResults usb read err:(-9) LIBUSB_ERROR_PIPE
[2014-11-30 20:32:37] AU3 33 attempted reset got err:(0) LIBUSB_SUCCESS
[2014-11-30 20:32:38] Accepted 096992f4 Diff 27/16 AU3 33
[2014-11-30 20:32:39] AU3 33 GetResults usb read err:(-9) LIBUSB_ERROR_PIPE
[2014-11-30 20:32:39] AU3 33 attempted reset got err:(0) LIBUSB_SUCCESS
[2014-11-30 20:32:40] AU3 33 GetResults usb read err:(-9) LIBUSB_ERROR_PIPE
[2014-11-30 20:32:41] AU3 33 attempted reset got err:(0) LIBUSB_SUCCESS
[2014-11-30 20:32:41] AU3 33 GetResults usb read err:(-9) LIBUSB_ERROR_PIPE
[2014-11-30 20:32:41] AU3 33 attempted reset got err:(0) LIBUSB_SUCCESS
[2014-11-30 20:32:41] AU3 33 GetResults usb read err:(-9) LIBUSB_ERROR_PIPE
[2014-11-30 20:32:41] AU3 33 attempted reset got err:(0) LIBUSB_SUCCESS