this bug affects me as well on a Gateway LT2104u netbook running 10.04 netbook edition. as far as i know, the LT2104u is just a re-branded version of the Acer AO532h.

it looks like the card reader actually shows up as a usb device, not a pci device. when i insert an sd card into the card reader, lsusb shows the following new device (which is not present when no memory card is inserted):

Bus 001 Device 004: ID 0cf2:6250 ENE Technology, Inc. 

when i remove the memory card, the above usb device goes away. /var/log/syslog only contains the following events from the time the memory card is inserted to when it's removed:

Jul  8 18:44:07 tweety kernel: [ 4474.384674] usb 1-5: new high speed USB device using ehci_hcd and address 3
Jul  8 18:44:07 tweety kernel: [ 4474.517824] usb 1-5: configuration #1 chosen from 1 choice
Jul  8 18:44:26 tweety kernel: [ 4493.382658] usb 1-5: USB disconnect, address 3

i will not have a chance to test the latest ubuntu cd image or the upstream kernel for 2 months. but i wanted to add the above information in case it is useful. i'm also including "lsusb -v" output for this device:

Bus 001 Device 005: ID 0cf2:6250 ENE Technology, Inc. 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x0cf2 ENE Technology, Inc.
  idProduct          0x6250 
  bcdDevice            1.00
  iManufacturer           1 ENE Flash  
  iProduct                2 UB6250       
  iSerial                 4 606569746801
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           32
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              498mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      6 
      bInterfaceProtocol     80 
      iInterface              0 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 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     0x0200  1x 512 bytes
        bInterval               0
Device Qualifier (for other device speed):
  bLength                10
  bDescriptorType         6
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  bNumConfigurations      1
Device Status:     0x0000
  (Bus Powered)