Let me know how the replacement modules work out please, because I finally got to play around with a Ubuntu desktop [14.04 64 bit] and the Arduino:
Here's what a successful connection looks like for reference:
[ 130.969290] usb 8-1.4.3: new full-speed USB device number 9 using xhci_hcd
[ 130.996269] usb 8-1.4.3: New USB device found, idVendor=2341, idProduct=0036
[ 130.996276] usb 8-1.4.3: New USB device strings: Mfr=2, Product=1, SerialNumber=0
[ 130.996282] usb 8-1.4.3: Product: Arduino Leonardo
[ 130.996286] usb 8-1.4.3: Manufacturer: Arduino LLC
[ 130.996547] usb 8-1.4.3: ep 0x82 - rounding interval to 1024 microframes, ep desc says 2040 microframes
[ 130.998979] cdc_acm 8-1.4.3:1.0: ttyACM0: USB ACM device
[ 138.893738] usb 8-1.4.3: USB disconnect, device number 9
[ 139.107180] usb 8-1.4.3: new full-speed USB device number 10 using xhci_hcd
[ 139.132276] usb 8-1.4.3: New USB device found, idVendor=2341, idProduct=8036
[ 139.132284] usb 8-1.4.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 139.132289] usb 8-1.4.3: Product: Arduino Leonardo
[ 139.132294] usb 8-1.4.3: Manufacturer: Arduino LLC
[ 139.134916] cdc_acm 8-1.4.3:1.0: This device cannot do calls on its own. It is not a modem.
[ 139.134984] cdc_acm 8-1.4.3:1.0: ttyACM0: USB ACM device
[ 139.145867] input: Arduino LLC Arduino Leonardo as /devices/pci0000:00/0000:00:04.0/0000:02:00.0/usb8/8-1/8-1.4/8-1.4.3/8-1.4.3:1.2/input/input21
[ 139.146271] hid-generic 0003:2341:8036.0005: input,hidraw3: USB HID v1.01 Mouse [Arduino LLC Arduino Leonardo] on usb-0000:02:00.0-1.4.3/input2
The numbers on the very left are timestamps in seconds. Notice how the Arduino connects at ~130s and then disconnects and reconnects at ~138s. This is correct and corresponds to the blinking of the LED ~8s after powering up.
The lsusb command will output the line
Bus 008 Device 010: ID 2341:8036 Arduino SA Leonardo (CDC ACM, HID)
Watching the syslogs using the 'dmesg' terminal command, I can see my machine disconnecting and reconnecting the Arduino about every 5 minutes. This is also correct functioning.
/dev/ttyACM0 is definitely the serial port to use, not /dev/tty0.
I tried the Arduino IDE package from the Ubuntu Software Center and downloaded directly from the Arduino site and both worked.
What is different between a working connection and the logs you posted begins with:
mtp-probe: bus: 3, device: 2 was not an MTP device
MTP stands for Media Transfer Protocol and is used by USB cameras and the like. 'mtp-probe' correctly detects that the Arduino is not an MTP device. However, It could end up being the problem.
More likely the problem starts with:
usbhid 3-2:1.2: can't add hid device: -71
A HID is a Human Interface Device; another USB communication standard.
I can't find much documentation of the -71 error code and a search returns lots of unsuccessful, or low level solutions mostly effecting keyboards and mice.
The only reported solution for this error code involved turning the USB setting 'XHCI Mode' to from 'Smart-Auto' to 'Enabled' in BIOS of your computer.
So after a bit of digging, I would suggest that you check your USB settings in the BIOS if the replacement boards still won't connect as a serial port.