Got the same problem with precise. The workaround from #5 works perfectly.

#connecting before workaround:
$ sudo dmesg -c
[25524.312051] usb 3-2: USB disconnect, device number 4
[25549.076020] usb 2-1: new high-speed USB device number 2 using ehci_hcd
[25549.144208] hub 2-0:1.0: unable to enumerate USB device on port 1
[25549.412019] usb 6-1: new full-speed USB device number 2 using uhci_hcd
[25549.557039] usb 6-1: not running at top speed; connect to a high speed hub
[25549.600165] usb-storage 6-1:1.0: Quirks match for vid 1e68 pid 001b: 8020
[25549.600199] scsi11 : usb-storage 6-1:1.0
[25561.098180] scsi 11:0:0:0: Direct-Access     TrekStor  DS maxi g.u          PQ: 0 ANSI: 2 CCS
[25561.098977] sd 11:0:0:0: Attached scsi generic sg4 type 0
[25561.104171] sd 11:0:0:0: [sdd] 2930277168 512-byte logical blocks: (1.50 TB/1.36 TiB)
[25561.109152] sd 11:0:0:0: [sdd] Write Protect is off
[25561.109157] sd 11:0:0:0: [sdd] Mode Sense: 34 00 00 00
[25561.114153] sd 11:0:0:0: [sdd] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[25561.142181]  sdd: sdd1
[25561.185156] sd 11:0:0:0: [sdd] Attached SCSI disk

### Unpluging the harddrive and:

$ sudo modprobe ehci_hcd
$ sudo modprobe uhci_hcd
$ sudo dmesg -c
[26626.176062] usb 6-1: USB disconnect, device number 2
[26695.512023] usb 2-1: new high-speed USB device number 3 using ehci_hcd
[26695.661594] usb-storage 2-1:1.0: Quirks match for vid 1e68 pid 001b: 8020
[26695.661630] scsi12 : usb-storage 2-1:1.0
[26707.438240] scsi 12:0:0:0: Direct-Access     TrekStor  DS maxi g.u          PQ: 0 ANSI: 2 CCS
[26707.439031] sd 12:0:0:0: Attached scsi generic sg4 type 0
[26707.439867] sd 12:0:0:0: [sdd] 2930277168 512-byte logical blocks: (1.50 TB/1.36 TiB)
[26707.440600] sd 12:0:0:0: [sdd] Write Protect is off
[26707.440606] sd 12:0:0:0: [sdd] Mode Sense: 34 00 00 00
[26707.441344] sd 12:0:0:0: [sdd] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[26707.469623]  sdd: sdd1
[26707.472222] sd 12:0:0:0: [sdd] Attached SCSI disk

$ hwinfo --usb 
> hal.1: read hal dataprocess 16364: arguments to dbus_move_error() were incorrect, assertion "(dest) == NULL || !dbus_error_is_set ((dest))" failed in file ../../dbus/dbus-errors.c line 282.
This is normally a bug in some application using the D-Bus library.
libhal.c 3483 : Error unsubscribing to signals, error=The name org.freedesktop.Hal was not provided by any .service files
05: SCSI c00.0: 10600 Disk                                      
  [Created at block.243]
  Unique ID: FKGF.wRFl5v6p_C7
  SysFS ID: /class/block/sdd
  SysFS BusID: 12:0:0:0
  SysFS Device Link: /devices/pci0000:00/0000:00:1d.7/usb2/2-1/2-1:1.0/host12/target12:0:0/12:0:0:0
  Hardware Class: disk
  Model: "TrekStor DS maxi g.u"
  Vendor: usb 0x1e68 "TrekStor"
  Device: usb 0x001b "DS maxi g.u"
  Serial ID: "20081114106D"
  Driver: "usb-storage", "sd"
  Driver Modules: "usb_storage"
  Device File: /dev/sdd (/dev/sg4)
  Device Files: /dev/sdd, /dev/disk/by-id/usb-TrekStor_DS_maxi_g.u_20081114106D-0:0, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:1:1.0-scsi-0:0:0:0
  Device Number: block 8:48-8:63 (char 21:4)
  Speed: 480 Mbps
  Module Alias: "usb:v1E68p001Bd0000dc00dsc00dp00ic08isc06ip50"
  Driver Info #0:
    Driver Status: uas is not active
    Driver Activation Cmd: "modprobe uas"
  Drive status: no medium
  Config Status: cfg=new, avail=yes, need=no, active=unknown
...

$ uname -a
Linux yeah 3.2.0-26-generic #41-Ubuntu SMP Thu Jun 14 17:49:24 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux