Bug confirmed. Neither rmmod ehci_hcd nor irqpoll are acceptable solutions because ehci_hcd disables USB 2.0 support and irqpoll is ridden with a lot of bugs for users (doing a quick irqpoll search on the internet reveals this). Also, adding kernel options such as irqpoll for all users should not acceptable. There must be another fix for this.

One small tidbit that may help: using almost identical hardware, with identical USB controllers, the computer with two USB ports has problems, the one with only one USB ports does not.

OUTPUT OF 1 USB PORT COMPUTER (w/o problems):


$ lsusb
Bus 004 Device 001: ID 0000:0000  
Bus 002 Device 001: ID 0000:0000  
Bus 001 Device 001: ID 0000:0000  
Bus 003 Device 001: ID 0000:0000


$ lspci
00:1d.0 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 01)
00:1d.1 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 01)
00:1d.2 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 01)
00:1d.7 USB Controller: Intel Corporation 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller (rev 01)


$ cat /proc/bus/usb/devices 
T:  Bus=04 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 2
B:  Alloc=  0/900 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 1.10 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0000 ProdID=0000 Rev= 2.06
S:  Manufacturer=Linux 2.6.17-10-generic uhci_hcd
S:  Product=UHCI Host Controller
S:  SerialNumber=0000:00:1d.2
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   2 Ivl=255ms

T:  Bus=03 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 2
B:  Alloc=  0/900 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 1.10 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0000 ProdID=0000 Rev= 2.06
S:  Manufacturer=Linux 2.6.17-10-generic uhci_hcd
S:  Product=UHCI Host Controller
S:  SerialNumber=0000:00:1d.1
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   2 Ivl=255ms

T:  Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 2
B:  Alloc=  0/900 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 1.10 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0000 ProdID=0000 Rev= 2.06
S:  Manufacturer=Linux 2.6.17-10-generic uhci_hcd
S:  Product=UHCI Host Controller
S:  SerialNumber=0000:00:1d.0
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   2 Ivl=255ms

T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480 MxCh= 6
B:  Alloc=  0/800 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=0000 ProdID=0000 Rev= 2.06
S:  Manufacturer=Linux 2.6.17-10-generic ehci_hcd
S:  Product=EHCI Host Controller
S:  SerialNumber=0000:00:1d.7
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   2 Ivl=256ms

$ cat /proc/interrupts 
           CPU0       
  0:    1439132          XT-PIC  timer
  1:       4630          XT-PIC  i8042
  2:          0          XT-PIC  cascade
  7:          2          XT-PIC  parport0
  8:          3          XT-PIC  rtc
  9:       4643          XT-PIC  acpi
 11:    1058243          XT-PIC  ehci_hcd:usb1, uhci_hcd:usb2, uhci_hcd:usb3, uhci_hcd:usb4, ohci1394, Intel 82801DB-ICH4, yenta, yenta, wifi0, Intel 82801DB-ICH4 Modem, radeon@pci:0000:01:00.0
 12:     119430          XT-PIC  i8042
 14:      20854          XT-PIC  ide0
NMI:          0 
LOC:          0 
ERR:          0
MIS:          0

$ lsmod | grep usb
usbcore               134912  3 uhci_hcd,ehci_hcd

OUTPUT OF 2 USB PORT COMPUTER (w/ problems):

$ lsusb
Bus 004 Device 001: ID 0000:0000  
Bus 003 Device 001: ID 0000:0000  
Bus 002 Device 001: ID 0000:0000  
Bus 001 Device 001: ID 0000:0000


$ lspci
00:1d.0 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 01)
00:1d.1 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 01)
00:1d.2 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 01)
00:1d.7 USB Controller: Intel Corporation 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller (rev 01)


$ cat /proc/bus/usb/devices 
T:  Bus=04 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480 MxCh= 6
B:  Alloc=  0/800 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=0000 ProdID=0000 Rev= 2.06
S:  Manufacturer=Linux 2.6.17-10-generic ehci_hcd
S:  Product=EHCI Host Controller
S:  SerialNumber=0000:00:1d.7
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   2 Ivl=256ms

T:  Bus=03 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 2
B:  Alloc=  0/900 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 1.10 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0000 ProdID=0000 Rev= 2.06
S:  Manufacturer=Linux 2.6.17-10-generic uhci_hcd
S:  Product=UHCI Host Controller
S:  SerialNumber=0000:00:1d.2
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   2 Ivl=255ms

T:  Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 2
B:  Alloc=  0/900 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 1.10 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0000 ProdID=0000 Rev= 2.06
S:  Manufacturer=Linux 2.6.17-10-generic uhci_hcd
S:  Product=UHCI Host Controller
S:  SerialNumber=0000:00:1d.1
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   2 Ivl=255ms

T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 2
B:  Alloc=  0/900 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 1.10 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0000 ProdID=0000 Rev= 2.06
S:  Manufacturer=Linux 2.6.17-10-generic uhci_hcd
S:  Product=UHCI Host Controller
S:  SerialNumber=0000:00:1d.0
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   2 Ivl=255ms


$ cat /proc/interrupts 
           CPU0       
  0:     223892          XT-PIC  timer
  1:        687          XT-PIC  i8042
  2:          0          XT-PIC  cascade
  7:          0          XT-PIC  parport0
  8:          3          XT-PIC  rtc
  9:       1031          XT-PIC  acpi
 11:     188219          XT-PIC  uhci_hcd:usb1, uhci_hcd:usb2, uhci_hcd:usb3, Intel 82801DB-ICH4, wifi0, yenta, yenta, radeon@pci:0000:01:00.0, ehci_hcd:usb4
 12:      45782          XT-PIC  i8042
 14:       6048          XT-PIC  ide0
 15:       7825          XT-PIC  ide1
NMI:          0 
LOC:          0 
ERR:          0
MIS:          0


$ lsmod | grep usb
usb_storage            75072  0 
scsi_mod              144648  3 sg,sd_mod,usb_storage
libusual               17040  1 usb_storage
usbcore               134912  5 ehci_hcd,usb_storage,libusual,uhci_hcd