Samuel,

below is the output of lsusb for my ACR122. The only relevant differences I could spot are version 2.03 vs. 2.07 and the max powere re

Bus 001 Device 005: ID 072f:2200 Advanced Card Systems, Ltd 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0         8
  idVendor           0x072f Advanced Card Systems, Ltd
  idProduct          0x2200 
  bcdDevice            2.03
  iManufacturer           1 ACS
  iProduct                2 ACR122U PICC Interface
  iSerial                 0 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           93
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              200mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           3
      bInterfaceClass        11 Chip/SmartCard
      bInterfaceSubClass      0 
      bInterfaceProtocol      0 
      iInterface              0 
      ChipCard Interface Descriptor:
        bLength                54
        bDescriptorType        33
        bcdCCID              1.00
        nMaxSlotIndex           0
        bVoltageSupport         7  5.0V 3.0V 1.8V 
        dwProtocols             2  T=1
        dwDefaultClock       4000
        dwMaxiumumClock      4000
        bNumClockSupported      0
        dwDataRate          10752 bps
        dwMaxDataRate      250000 bps
        bNumDataRatesSupp.      0
        dwMaxIFSD             256
        dwSyncProtocols  00000000 
        dwMechanical     00000000 
        dwFeatures       00020040
          Auto parameter negotation made by CCID
          Short APDU level exchange
        dwMaxCCIDMsgLen       271
        bClassGetResponse      00
        bClassEnvelope         00
        wlcdLayout           none
        bPINSupport             0 
        bMaxCCIDBusySlots       1
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval               2
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
Device Status:     0x0000
  (Bus Powered)